OpenSE4 0.15.1

OpenSE4 is an open-source engine for Space Empires IV Deluxe. It plays the classic game on your own installed copy of Space Empires IV Deluxe and contains nothing from the original game.

OpenSE4 is not affiliated with, endorsed by or sponsored by the game's publishers.

What changed since 0.15.0

A player asked on GitHub (#19) why a computer empire with a "Brotherly" mood still refused a treaty while at war. We checked the original: SE4's computer players refuse every treaty proposal while they are at war with you, whatever their mood. They accept one only after 12 to 15 turns of peace, depending on the race. OpenSE4 already did this. While checking, we found and fixed eleven smaller differences in how the computer players answer proposals and trades:

• Counter-proposals. When a computer player turns a treaty down, it sometimes offers a lesser treaty instead of a plain refusal. It no longer sends both. The same goes for trades.
• The wait after a war is counted first thing in the computer's turn, as in SE4. So the wait ends on the right turn, and a computer player no longer offers a treaty right after you declare war on it.
• Treaties inside trades. A War item in a trade is judged like any other treaty.
• Proposals. The tests and random rolls come in the original's order, including in Team Mode.
• Ministers. An empire with every minister off keeps its war counts unchanged.
• Attack choices use the anger the computer's turn began with. The in-system attacks and anti-planet drones pick their targets without sorting by anger.
• Anger adds battles, intelligence and stellar events in the original's order. This only matters with modded tables.
• Messages. A computer player can send two messages to the same empire in one turn, as in SE4. The one-message limit applies to your own messages.
• Trades. A trade asking for something the computer doesn't have gets the original's kind of reply.

Compatibility

0.15.1 plays with 0.15.0 (network protocol 10) and reads its saves (save format 11). It does not play with 0.14.x. The computer players play somewhat differently. Every player in a network game must have the same game-changing mods.

Downloads

File	For
OpenSE4-0.15.1-windows-x86_64-setup.exe	64-bit Windows 7 SP1 to 11: the installer
OpenSE4-0.15.1-windows-x86_64.zip	64-bit Windows 7 SP1 to 11: the same programs to run from any folder
OpenSE4-0.15.1-linux-x86_64.tar.gz	64-bit Linux on PCs with glibc 2.34 or later (Ubuntu 22.04, Debian 12, Fedora 35, SteamOS 3 and newer)
OpenSE4-0.15.1-linux-aarch64.tar.gz	64-bit ARM Linux with glibc 2.34 or later (Raspberry Pi OS 64-bit, Asahi, Ubuntu and Debian on ARM)
OpenSE4-0.15.1-linux-armhf.tar.gz	32-bit ARM Linux (ARMv7 with NEON) with glibc 2.34 or later (Raspberry Pi OS 32-bit)
OpenSE4-0.15.1-SHA256SUMS.txt	SHA-256 checksums of the downloads

Every download holds five programs:

• the game (opense4);
• the dedicated server for network and play-by-e-mail games (opense4-server);
• a data checker (opense4-datacheck);
• the saved-game converter (opense4-convert);
• the modding tool (opense4-sdk).

It also holds the Hegemon mod (mods/; turn it on in the Mods window), the modder's documents and examples (sdk/) and, in the zip and tarballs, PORTABLE-README.txt. Libraries, our own fonts, the manual and the lessons are built in.

Running it

• Windows: run the installer, then start OpenSE4 from the Start menu, or unpack the zip and run opense4.exe. Neither is code-signed yet, so Windows SmartScreen may warn the first time ("More info", then "Run anyway").
• Linux, on a PC or on ARM: unpack and run ./opense4, or run ./install-desktop-entry.sh once to start it from your desktop's application list. On ARM boards without a Steam install, copy the game's files from another computer (see docs/SETUP.md).

The game looks for a Steam install of Space Empires IV Deluxe. See README.md for other locations and command-line options (opense4 --help). Modders start with sdk/docs/README.md.

Known limitations

• This is still an early build, marked as a pre-release.

• Details still being checked: where the original's behaviour couldn't be pinned down, OpenSE4 makes a stated choice. These choices are listed as open questions in docs/spec/, for example how the original treats a mine group chosen in battle, or the default names past the tenth fleet.

• Original .map files: reading them has only been tested with maps OpenSE4 wrote, since no map file from the original was at hand. Reports with real map files are welcome.

• Not yet tested on real hardware:

  • Windows 7: only under Wine, with each program's imports checked against what Windows 7 provides.
  • ARM: only through emulation and native ARM test runners; the game window hasn't been opened on a real ARM graphics chip yet.

  Reports are welcome.

• Scripts run on MicroPython: in-game scripts use a built-in, sandboxed Python (MicroPython with additions), so libraries such as numpy are only available to external bots.

• Rules mods near their time limit: a rules mod that runs very close to its per-turn time limit could, rarely, replay a turn slightly differently.

• Hegemon rarely finishes off an empire within 150 turns; it wins by growing far ahead.

• Following warps: the view follows your ships through warp points in local, hotseat and e-mail games, but not yet for players who join someone else's network game.

• In network and e-mail games, every battle is resolved strategically, as in the original.

License

OpenSE4 is free software under the GNU General Public License, version 3 or later. The Noto Sans fonts are under the SIL Open Font License. THIRD_PARTY_NOTICES.txt in each download lists the bundled libraries and their licences, among them MicroPython and miniz.

OpenSE4 0.15.0

OpenSE4 is an open-source engine for Space Empires IV Deluxe. It plays the classic game on your own installed copy of Space Empires IV Deluxe and contains nothing from the original game.

OpenSE4 is not affiliated with, endorsed by or sponsored by the game's publishers.

What changed since 0.14.1

This release is an accuracy pass. While fixing a report earlier this week, we found that the tool we use to read the original game's code had been hiding part of many routines from us. About 400 routines had lost real game logic that way, and more were misread as returning early. We repaired the tool, then checked every area of OpenSE4 against the complete code of SE4 again: movement, orders, cargo and colonization; the economy and events; combat; the computer players; research, intelligence and diplomacy; the galaxy, setup and saved games; and the interface. About 150 differences were found and corrected. As before, OpenSE4's own additions stay, and where one changes what you see or how the game plays, it is now an option that starts off. See "New options" below.

Ship movement, exactly as in SE4

• The turn is invisible. As in SE4, a ship doesn't visibly rotate before it moves: it waits on its square for the time of the turn, then slides off already facing its new way. We checked this in the running original.
• One group at a time, as in SE4, now with the original's details:
  • your ships at the start of your turn are each selected, then moved;
  • a fleet is drawn as its first ship;
  • a minefield hit plays its explosion, sound and pause;
  • the move into a battle is shown before the battle.
• A turn's start stops at the Attack Sector question. Later groups move only after you answer.
• Input during moves follows the original:
  • after a map-click order, clicks and keys wait until the ships have moved;
  • after an order button, you can carry on.
  • A click or key at the start of your turn still skips the animation.
• The original's selection after a move: a move order leaves the top-left square of the system current, as in SE4.
• Computer players' moves are no longer animated, as in SE4. A new option brings that back (see below).
• Network games: your own ships now move square by square in network games too.

Rules corrected (selected)

• Orders and cargo:

  • Load Cargo takes only from your colonies and bases, never from other ships, and a plague doesn't stop it.
  • Tagged ships share one worked-out Explore or Colonize plan.
  • Set Patrol starts only when the route is closed.
  • Most failed orders say nothing, as in SE4; the new "Explain failed orders" option brings our messages back.

• Colonization: founding a colony gives the empire 100 experience. The colony ship unloads by the Drop Cargo rules, and a Medical Bay cures plague as it passes.

• Fleets: default fleet names count every fleet ever made. Empty fleets last until the game is loaded again.

• Economy and events:

  • a captured capital stays a capital;
  • a lost planet's happiness events come only when its people die out;
  • starting population leaves out the storage trait;
  • at most five timed events wait at once;
  • riots follow anger alone;
  • Team Mode ignores treaty happiness;
  • the Planetary minister's mood reports are new.

• Combat:

  • targets are picked with the original's sort and the original's strength, size and damage measures;
  • a missile's hit credits no experience;
  • launched units and battle minefields are real objects at once;
  • every ground unit rolls;
  • damage pools are capped.

• Computer players:

  • their fleets keep receiving orders after defending;
  • fleet roles and sizes follow the fleets in being;
  • attack, patrol and exploration follow the original's rules;
  • their construction list stops where SE4's does;
  • their demand lists are forgotten when a game is loaded.

  Their pace is now closer to the original's in exploration, infrastructure and ships.

• Diplomacy and intelligence:

  • a technology item in a trade gives one level;
  • only the newest message from an empire can be answered;
  • Break Treaty ends a war;
  • surrendered ships leave their fleets;
  • spying results and failures follow the original;
  • Select Package adds amounts in the original's steps.

• End of game:

  • once a game is decided, its last turn skips the economy and the computer players;
  • a simultaneous game goes on after a victory, as in SE4.

• Galaxy and setup:

  • Create Black Hole destroys planets outright;
  • every ship in a group with a stellar manipulation device acts;
  • Construct needs the exact size;
  • Quick Start builds your empire like a computer player's.

• Saved games:

  • experience in saves of the original from versions 1.40 to 1.45 is read correctly;
  • a save holding designs owned by no player imports.

• Command line: the original's command line behaves as in SE4: missing files, -nd, and signing in.

• Interface:

  • tags stay through the ship cycle until Shift+C or a sector click;
  • the ship, fleet and colony cycles continue where they left off;
  • the sector list shows a design's class only under your own ships;
  • Drop Cargo asks the cargo kind first;
  • held keys repeat;
  • the Component Report shows the original's lines.

The rules are written in docs/spec/, each corrected answer marked "corrected 2026-10-14, complete listing". What OpenSE4 still does differently on purpose is in docs/PARITY_GAPS.md.

New options (all off by default, under Options → OpenSE4)

• Also animate other empires' and simultaneous turns' moves
• Explain failed orders
• More in item reports
• Say on the map why a click fired nothing (tactical combat)
• Clear tags when selecting a ship elsewhere
• Show enemy designs' details
• Act once on held keys
• Game Setup's Save To File saves the designs

Compatibility

0.15.0 does not play with 0.14.x. Network and e-mail games need everyone on 0.15.0 (protocol 10). 0.15.0 loads saves from 0.14.x and older (save format 11 now), but 0.14.x cannot load 0.15.0's saves. Games continued from a save play by the corrected rules from then on, and the computer players play differently. Every player in a network game must have the same game-changing mods.

Downloads

File	For
OpenSE4-0.15.0-windows-x86_64-setup.exe	64-bit Windows 7 SP1 to 11: the installer
OpenSE4-0.15.0-windows-x86_64.zip	64-bit Windows 7 SP1 to 11: the same programs to run from any folder
OpenSE4-0.15.0-linux-x86_64.tar.gz	64-bit Linux on PCs with glibc 2.34 or later (Ubuntu 22.04, Debian 12, Fedora 35, SteamOS 3 and newer)
OpenSE4-0.15.0-linux-aarch64.tar.gz	64-bit ARM Linux with glibc 2.34 or later (Raspberry Pi OS 64-bit, Asahi, Ubuntu and Debian on ARM)
OpenSE4-0.15.0-linux-armhf.tar.gz	32-bit ARM Linux (ARMv7 with NEON) with glibc 2.34 or later (Raspberry Pi OS 32-bit)
OpenSE4-0.15.0-SHA256SUMS.txt	SHA-256 checksums of the downloads

Every download holds five programs:

• the game (opense4);
• the dedicated server for network and play-by-e-mail games (opense4-server);
• a data checker (opense4-datacheck);
• the saved-game converter (opense4-convert);
• the modding tool (opense4-sdk).

It also holds the Hegemon mod (mods/; turn it on in the Mods window), the modder's documents and examples (sdk/) and, in the zip and tarballs, PORTABLE-README.txt. Libraries, our own fonts, the manual and the lessons are built in.

Running it

• Windows: run the installer, then start OpenSE4 from the Start menu, or unpack the zip and run opense4.exe. Neither is code-signed yet, so Windows SmartScreen may warn the first time ("More info", then "Run anyway").
• Linux, on a PC or on ARM: unpack and run ./opense4, or run ./install-desktop-entry.sh once to start it from your desktop's application list. On ARM boards without a Steam install, copy the game's files from another computer (see docs/SETUP.md).

The game looks for a Steam install of Space Empires IV Deluxe. See README.md for other locations and command-line options (opense4 --help). Modders start with sdk/docs/README.md.

Known limitations

• This is still an early build, marked as a pre-release.

• Details still being checked: where the original's behaviour couldn't be pinned down, OpenSE4 makes a stated choice. These choices are listed as open questions in docs/spec/, for example how the original treats a mine group chosen in battle, or the default names past the tenth fleet.

• Original .map files: reading them has only been tested with maps OpenSE4 wrote, since no map file from the original was at hand. Reports with real map files are welcome.

• Not yet tested on real hardware:

  • Windows 7: only under Wine, with each program's imports checked against what Windows 7 provides.
  • ARM: only through emulation and native ARM test runners; the game window hasn't been opened on a real ARM graphics chip yet.

  Reports are welcome.

• Scripts run on MicroPython: in-game scripts use a built-in, sandboxed Python (MicroPython with additions), so libraries such as numpy are only available to external bots.

• Rules mods near their time limit: a rules mod that runs very close to its per-turn time limit could, rarely, replay a turn slightly differently.

• Hegemon rarely finishes off an empire within 150 turns; it wins by growing far ahead.

• Following warps: the view follows your ships through warp points in local, hotseat and e-mail games, but not yet for players who join someone else's network game.

• In network and e-mail games, every battle is resolved strategically, as in the original.

License

OpenSE4 is free software under the GNU General Public License, version 3 or later. The Noto Sans fonts are under the SIL Open Font License. THIRD_PARTY_NOTICES.txt in each download lists the bundled libra...

OpenSE4 0.14.1

OpenSE4 is an open-source engine for Space Empires IV Deluxe. It plays the classic game on your own installed copy of Space Empires IV Deluxe and contains nothing from the original game.

OpenSE4 is not affiliated with, endorsed by or sponsored by the game's publishers.

What changed since 0.14.0

A player on Discord pointed out that every ship moved at once, and that a long move slid along one straight line. In SE4, each group makes its own move in turn: a lone ship, a fleet, or ships ordered together. That is part of the fun of watching your designs fly.

• One group at a time. Each group makes its whole move square by square, turning at each bend, before the next group starts. This happens at the start of your turn, when your ships carry on their orders, and when you give an order during the turn.
• The view follows your ships. At the start of your turn the view follows each of your groups as it moves. After a warp jump it moves to the arrival system once the ship reaches the warp point.
• An option for all at once. Options has a new choice under OpenSE4, "Ship movement": one group at a time (the default, as in SE4) or all at once. A click or a key still skips the animation.
• The movement replay. In simultaneous games the Play Movement Log replay also moves each ship on its own, one after another.
• Differences from SE4, on purpose:
  • You also see the computer players' visible ships move, where SE4 shows a black "taking turn" screen.
  • In network and e-mail games, your copy of the game only gets the end positions from the host. Each group glides straight to its new square there, one after another.

Compatibility

0.14.1 plays with 0.14.0 (network protocol 9) and reads its saves (save format 10). It still does not play with 0.13.0. Every player in a network game must have the same game-changing mods.

Downloads

File	For
OpenSE4-0.14.1-windows-x86_64-setup.exe	64-bit Windows 7 SP1 to 11: the installer
OpenSE4-0.14.1-windows-x86_64.zip	64-bit Windows 7 SP1 to 11: the same programs to run from any folder
OpenSE4-0.14.1-linux-x86_64.tar.gz	64-bit Linux on PCs with glibc 2.34 or later (Ubuntu 22.04, Debian 12, Fedora 35, SteamOS 3 and newer)
OpenSE4-0.14.1-linux-aarch64.tar.gz	64-bit ARM Linux with glibc 2.34 or later (Raspberry Pi OS 64-bit, Asahi, Ubuntu and Debian on ARM)
OpenSE4-0.14.1-linux-armhf.tar.gz	32-bit ARM Linux (ARMv7 with NEON) with glibc 2.34 or later (Raspberry Pi OS 32-bit)
OpenSE4-0.14.1-SHA256SUMS.txt	SHA-256 checksums of the downloads

Every download holds five programs:

• the game (opense4);
• the dedicated server for network and play-by-e-mail games (opense4-server);
• a data checker (opense4-datacheck);
• the saved-game converter (opense4-convert);
• the modding tool (opense4-sdk).

It also holds the Hegemon mod (mods/; turn it on in the Mods window), the modder's documents and examples (sdk/) and, in the zip and tarballs, PORTABLE-README.txt. Libraries, our own fonts, the manual and the lessons are built in.

Running it

• Windows: run the installer, then start OpenSE4 from the Start menu, or unpack the zip and run opense4.exe. Neither is code-signed yet, so Windows SmartScreen may warn the first time ("More info", then "Run anyway").
• Linux, on a PC or on ARM: unpack and run ./opense4, or run ./install-desktop-entry.sh once to start it from your desktop's application list. On ARM boards without a Steam install, copy the game's files from another computer (see docs/SETUP.md).

The game looks for a Steam install of Space Empires IV Deluxe. See README.md for other locations and command-line options (opense4 --help). Modders start with sdk/docs/README.md.

Known limitations

• This is still an early build, marked as a pre-release.

• Details still being checked: where the original's behaviour couldn't be pinned down, OpenSE4 makes a stated choice. These choices are listed as open questions in docs/spec/, for example how the original treats a mine group chosen in battle, or the default names past the tenth fleet.

• Original .map files: reading them has only been tested with maps OpenSE4 wrote, since no map file from the original was at hand. Reports with real map files are welcome.

• Not yet tested on real hardware:

  • Windows 7: only under Wine, with each program's imports checked against what Windows 7 provides.
  • ARM: only through emulation and native ARM test runners; the game window hasn't been opened on a real ARM graphics chip yet.

  Reports are welcome.

• Scripts run on MicroPython: in-game scripts use a built-in, sandboxed Python (MicroPython with additions), so libraries such as numpy are only available to external bots.

• Rules mods near their time limit: a rules mod that runs very close to its per-turn time limit could, rarely, replay a turn slightly differently.

• Hegemon rarely finishes off an empire within 150 turns; it wins by growing far ahead.

• Following warps: the view follows your ships through warp points in local, hotseat and e-mail games, but not yet for players who join someone else's network game.

• In network and e-mail games, every battle is resolved strategically, as in the original.

License

OpenSE4 is free software under the GNU General Public License, version 3 or later. The Noto Sans fonts are under the SIL Open Font License. THIRD_PARTY_NOTICES.txt in each download lists the bundled libraries and their licences, among them MicroPython and miniz.

OpenSE4 0.14.0

OpenSE4 is an open-source engine for Space Empires IV Deluxe. It plays the classic game on your own installed copy of Space Empires IV Deluxe and contains nothing from the original game.

OpenSE4 is not affiliated with, endorsed by or sponsored by the game's publishers.

What changed since 0.13.0

This release fixes the reports a player filed on GitHub after 0.12.0 (issues #11 to #18, and a follow-up on #5). Each one was first checked against the original game.

While checking #18 we found that the tool we use to read the original's code had been cutting part of many routines off. With a complete reading, we checked again every rule in our notes that said the original never does something, and corrected the ones that were wrong.

From the players' reports

• Movement after a battle (#13). A ship that loses engines has its movement for the turn cut to its new maximum at once, in battle or otherwise, whoever's turn it is. A damaged ship told to move now goes straight away with what it has left. Before, the report could show more movement than the maximum (4 / 3), and the ship could then lose all of it.
• Claim every system we colonize (#18). This Empire Option now works as in SE4: founding a colony with it on claims the colony's system, for computer players too. The systems of every starting planet are claimed when a game begins.
• Seekers keep a battle going (#17). As in the original, a battle goes on while any missile is still flying, even when its launcher is gone, and a missile goes when its target does. No stray dot is left on the Strategic Combat map. The map draws ships and missiles as small squares and planets as outlines, as SE4 does.
• Right-click on an empire's flag (#15) in a ship, base, planet or unit report opens that empire's Race Report. Its first page now shows what the original's does: treaty, trade and mood, then age, culture, demeanor and home world.
• Damage counts components (#16). The Ship Report's Damage line, the Comps page and the Ships window show destroyed components out of the design's total, with the original's red and green bar. Repair counts the same way. Pointing at the line still shows the structure lost.
• A taller designer (#14). On screens of 1024x768 and up, the Ship Design and Unit Design window is as tall as the list windows, and the extra room goes to Warnings and Component Details. A component's whole report, damage by range included, fits without scrolling. At 800x600 the window keeps its old size.
• What research brings (#11). A right-click on a research project or an area opens the area's report (since 0.13.0). The report now also lists what each later level brings, so you can see when the next kind of armor comes.
• Units' Amount list (#12). It was checked at every text size and layout, and all its choices show.
• Only Latest and Upgrade (#5). These still group parts as the original does, by the family number in the data. In the stock data, Phased Shield Generators share a family with Shield Generators, and Small Emissive Armor shares one with Small Armor. Untick Only Latest to see them all.

Rules corrected against the complete reading

• A colony taken in ground combat keeps its slow (emergency) mode. Its queue is emptied as in a treaty transfer.
• Subjugated computer players refuse any trade or gift that holds a treaty.
• Computer players start with their own strategy list from the AI files, not with the default list.
• The original's command line. opense4 GAMEFILE PASSWORD [PLAYER [MODFOLDER]] hosts a play-by-e-mail turn with the host password, or opens player N's turn after checking the data files, as in SE4. See README.md and docs/MULTIPLAYER.md.
  • A shortcut that passed only a mod folder this way now needs --mod=.
• Formation slots: the formation report no longer shows a leader's design type, which the original never uses.

The rules are written in docs/spec/. What OpenSE4 still does differently on purpose is listed in docs/PARITY_GAPS.md.

Compatibility

0.14.0 does not play with 0.13.0. Network and e-mail games need everyone on 0.14.0 (protocol 9), because rules that each computer applies changed. 0.14.0 loads 0.13.0's saves (save format 10), and older ones back to 0.7.0. Games continued from a save play by the new rules from then on. The computer players play somewhat differently. Every player in a network game must have the same game-changing mods.

Downloads

File	For
OpenSE4-0.14.0-windows-x86_64-setup.exe	64-bit Windows 7 SP1 to 11: the installer
OpenSE4-0.14.0-windows-x86_64.zip	64-bit Windows 7 SP1 to 11: the same programs to run from any folder
OpenSE4-0.14.0-linux-x86_64.tar.gz	64-bit Linux on PCs with glibc 2.34 or later (Ubuntu 22.04, Debian 12, Fedora 35, SteamOS 3 and newer)
OpenSE4-0.14.0-linux-aarch64.tar.gz	64-bit ARM Linux with glibc 2.34 or later (Raspberry Pi OS 64-bit, Asahi, Ubuntu and Debian on ARM)
OpenSE4-0.14.0-linux-armhf.tar.gz	32-bit ARM Linux (ARMv7 with NEON) with glibc 2.34 or later (Raspberry Pi OS 32-bit)
OpenSE4-0.14.0-SHA256SUMS.txt	SHA-256 checksums of the downloads

Every download holds five programs:

• the game (opense4);
• the dedicated server for network and play-by-e-mail games (opense4-server);
• a data checker (opense4-datacheck);
• the saved-game converter (opense4-convert);
• the modding tool (opense4-sdk).

It also holds the Hegemon mod (mods/; turn it on in the Mods window), the modder's documents and examples (sdk/) and, in the zip and tarballs, PORTABLE-README.txt. Libraries, our own fonts, the manual and the lessons are built in.

Running it

• Windows: run the installer, then start OpenSE4 from the Start menu, or unpack the zip and run opense4.exe. Neither is code-signed yet, so Windows SmartScreen may warn the first time ("More info", then "Run anyway").
• Linux, on a PC or on ARM: unpack and run ./opense4, or run ./install-desktop-entry.sh once to start it from your desktop's application list. On ARM boards without a Steam install, copy the game's files from another computer (see docs/SETUP.md).

The game looks for a Steam install of Space Empires IV Deluxe. See README.md for other locations and command-line options (opense4 --help). Modders start with sdk/docs/README.md.

Known limitations

• This is still an early build, marked as a pre-release.

• Details still being checked: where the original's behaviour couldn't be pinned down, OpenSE4 makes a stated choice. These choices are listed as open questions in docs/spec/, for example how the original treats a mine group chosen in battle, or the default names past the tenth fleet.

• Original .map files: reading them has only been tested with maps OpenSE4 wrote, since no map file from the original was at hand. Reports with real map files are welcome.

• Not yet tested on real hardware:

  • Windows 7: only under Wine, with each program's imports checked against what Windows 7 provides.
  • ARM: only through emulation and native ARM test runners; the game window hasn't been opened on a real ARM graphics chip yet.

  Reports are welcome.

• Scripts run on MicroPython: in-game scripts use a built-in, sandboxed Python (MicroPython with additions), so libraries such as numpy are only available to external bots.

• Rules mods near their time limit: a rules mod that runs very close to its per-turn time limit could, rarely, replay a turn slightly differently.

• Hegemon rarely finishes off an empire within 150 turns; it wins by growing far ahead.

• Following warps: the view follows your ships through warp points in local, hotseat and e-mail games, but not yet for players who join someone else's network game.

• In network and e-mail games, every battle is resolved strategically, as in the original.

License

OpenSE4 is free software under the GNU General Public License, version 3 or later. The Noto Sans fonts are under the SIL Open Font License. THIRD_PARTY_NOTICES.txt in each download lists the bundled libraries and their licences, among them MicroPython and miniz.

OpenSE4 0.13.0

OpenSE4 is an open-source engine for Space Empires IV Deluxe. It plays the classic game on your own installed copy of Space Empires IV Deluxe and contains nothing from the original game.

OpenSE4 is not affiliated with, endorsed by or sponsored by the game's publishers.

What changed since 0.12.0

This release is a feature-parity pass. Every window of the original was compared with OpenSE4's, together with the rules behind each button. About 130 differences were found and brought in line with SE4. OpenSE4's own additions stay as they were: the Learn window, mods and the SDK, the settings window and the encrypted network games.

The original's tutorial, scenarios, empires and maps

• The original's tutorial and scenarios play again. The Learn window's Scenarios tab lists the scenarios in your install's Scenarios folder (the Tutorial too) next to the mods' scenarios. Their pages appear at the right turns. Ctrl+H shows the last page again, and in the tutorial so do the T buttons.
• Older saved games. Saved games of the original from version 1.40 load, not just 1.95, which covers the tutorial's game.
• Empire files (.emp). Game Setup's Add Existing lists the stock empires in your install's Empires folder and those of classic mods, beside OpenSE4's own empire files. Empires can also be saved for SE IV. OpenSE4's own empire files now keep the password, e-mail, ministers, options and type lists.
• Map files (.map). Load Map reads the original's maps, and Save Map can write them. opense4-convert converts maps both ways.

Orders and the main window

• Ship selection. Space, Ctrl+N, Ctrl+B and the arrows cycle through the same ships as in SE4: ships that can still move, skipping bases, mothballed ships and sentries.
• Cloak and Decloak act at once.
• Set Patrol adds each point as you click and ends when you click the ship itself. Enter and right-click still end it too.
• Location keys. Waypoints are numbered 1–10. Alt+digit, Ctrl+T and Ctrl+R ask for a sector to click.
• Names. Change Name refuses a name another object already has.
• Remote cargo orders. Load, Drop, Launch and Recover Remotely pick the place first, then a kind of cargo, and move every design of that kind.
• Launch / Recover window. It acts at once on the ship or colony you click, and warns when a launch can't happen.
• Abandon Planet is now an order you can still take back in a simultaneous game.
• Scrap window. Unmothball needs a space yard. A Scrap-window order that fails no longer clears the ship's other orders. The window gains Order By Name/Class and Select All/None.
• Fleets. Create Fleet starts an empty fleet named Alpha Fleet, Beta Fleet and so on.
• Stellar Manipulation picks its target after you confirm. Open Warp Point picks its destination on the Galaxy Map, and Construct asks for the planet size.
• Galaxy Map. Notes open for any system, and an unexplored system is no longer named.
• Quitting. Closing the game window during a game now asks first.

Colonies, construction and empire management

• Units. Adding units asks how many, and One Turn's Worth is among the choices.
• What queues accept follows the original. The list of what can be built is grouped under headings.
• Colony and design types. Colony types and design types can be added and deleted.
• Queue types belong to your empire and are saved with the game.
• Complete AI no longer stays on behind the individual minister switches.
• Strategies gain the Damage and Launching pages, with Drones Per Target.
• Windows remember their tab: Designs, Empires, Colonies and Set Construction Queue.

Diplomacy and reports

• Asking for a gift or tribute carries a package.
• Answering from the Empires window. Communicate opened from an empire's portrait offers the answers to that empire's latest message.
• Treaties follow the original:
  • which treaties can be proposed;
  • subjugated empires cannot sign treaties;
  • who can see which cell of the Treaty Grid.
• Empires window. Mood, trade, tariff and pending-offer lines.
• Comparisons are drawn from what you could see at the time.
• Scores and Victory Conditions show what the original shows.

Combat

• Boarding. A message reports how a boarding went.
• Mines can be laid in battle.
• The weapons you tick reset with each selection.
• Next and previous piece prefer group leaders.
• Target panel. It shows the damage each hit did.
• Ram and Capture refuse in the original's order. Seekers and obstacles can be rammed.
• Combat Simulator. It runs with one side.

Designs, research and intelligence

• Intelligence projects ask for their target (a ship, planet, technology or empire), and the project's box shows it.
• Technology Tree lists every area and exports like the original.
• Create Design. Its size, component group and mount lists are the original's windows, and Condensed View regroups the design's components.

Setup and game flow

• Victory. When a victory condition is met in a turn-based game, everyone plays one last turn, then the game reports it is complete.
• Failed orders in turn-based games show a message box at once.
• Next Player and Login To Game work as in the original. Loading a simultaneous game asks who signs in.
• Progress window while a turn is processed.
• Game Setup controls. The victory conditions, characteristics and caps step and limit as in the original. Create Empire checks the emperor's name, the culture and a gas giant's atmosphere.
• The command line's fourth argument names a mod folder, as in SE4.
• Network games play the original's sounds.

The rules each change follows are written in docs/spec/. What OpenSE4 still does differently on purpose is listed in docs/PARITY_GAPS.md.

Compatibility

0.13.0 does not play with 0.12.0. Network and e-mail games need everyone on 0.13.0 (protocol 8). 0.13.0 loads saved games from 0.12.0 and 0.11.0 (save format 9) and back to 0.7.0, but 0.12.0 cannot load 0.13.0's saves (save format 10). The computer players play somewhat differently, because some rules they use changed. Every player in a network game must have the same game-changing mods.

Downloads

File	For
OpenSE4-0.13.0-windows-x86_64-setup.exe	64-bit Windows 7 SP1 to 11: the installer
OpenSE4-0.13.0-windows-x86_64.zip	64-bit Windows 7 SP1 to 11: the same programs to run from any folder
OpenSE4-0.13.0-linux-x86_64.tar.gz	64-bit Linux on PCs with glibc 2.34 or later (Ubuntu 22.04, Debian 12, Fedora 35, SteamOS 3 and newer)
OpenSE4-0.13.0-linux-aarch64.tar.gz	64-bit ARM Linux with glibc 2.34 or later (Raspberry Pi OS 64-bit, Asahi, Ubuntu and Debian on ARM)
OpenSE4-0.13.0-linux-armhf.tar.gz	32-bit ARM Linux (ARMv7 with NEON) with glibc 2.34 or later (Raspberry Pi OS 32-bit)
OpenSE4-0.13.0-SHA256SUMS.txt	SHA-256 checksums of the downloads

Every download holds five programs:

• the game (opense4);
• the dedicated server for network and play-by-e-mail games (opense4-server);
• a data checker (opense4-datacheck);
• the saved-game converter (opense4-convert);
• the modding tool (opense4-sdk).

It also holds the Hegemon mod (mods/; turn it on in the Mods window), the modder's documents and examples (sdk/) and, in the zip and tarballs, PORTABLE-README.txt. Libraries, our own fonts, the manual and the lessons are built in.

Running it

• Windows: run the installer, then start OpenSE4 from the Start menu, or unpack the zip and run opense4.exe. Neither is code-signed yet, so Windows SmartScreen may warn the first time ("More info", then "Run anyway").
• Linux, on a PC or on ARM: unpack and run ./opense4, or run ./install-desktop-entry.sh once to start it from your desktop's application list. On ARM boards without a Steam install, copy the game's files from another computer (see docs/SETUP.md).

The game looks for a Steam install of Space Empires IV Deluxe. See README.md for other locations and command-line options (opense4 --help). Modders start with sdk/docs/README.md.

Known limitations

• This is still an early build, marked as a pre-release.

• Details still being checked: where the original's behaviour couldn't be pinned down, OpenSE4 makes a stated choice. These choices are listed as open questions in docs/spec/, for example how the original treats a mine group chosen in battle, or the default names past the tenth fleet.

• Original .map files: reading them has only been tested with maps OpenSE4 wrote, since no map file from the original was at hand. Reports with real map files are welcome.

• Not yet tested on real hardware:

  • Windows 7: only under Wine, with each program's imports checked against what Windows 7 provides.
  • ARM: only through emulation and native ARM test runners; the game window hasn't been opened on a real ARM graphics chip yet.

  Reports are welcome.

• Scripts run on MicroPython: in-game scripts use a built-in, sandboxed Python (MicroPython with additions), so libraries such as numpy are only available to external bots.

• Rules mods near their time limit: a rules mod that runs very close to its per-turn time limit could, rarely, replay a turn slightly differently.

• Hegemon rarely finishes off an empire within 150 turns; it wins by growing far ahead.

• Following warps: the view follows your ships through warp points in local, hotseat and e-mail games, but not yet for players who join someone else's network game.

• In network and e-mail games, every battle is resolved strategically, as in the original.

License

OpenSE4 is free software under the GNU General Public License, version 3 or later. The Noto Sans fonts are under the SIL Open Font License. THIRD_PARTY_NOTICES.txt in each download lists the bundled libraries and their licences, ...

OpenSE4 0.12.0

OpenSE4 is an open-source engine for Space Empires IV Deluxe. It plays the classic game on your own installed copy of Space Empires IV Deluxe and contains nothing from the original game.

OpenSE4 is not affiliated with, endorsed by or sponsored by the game's publishers.

What changed since 0.11.0

Thank you for the reports on Discord. This release answers them, and completes the modding SDK's documentation.

Ship movement

• The Log waits for your ships. When you end a turn, the ships you are looking at now finish moving first, as in SE4. The Log, and anything else the new turn brings (battles to watch, questions such as a new colony's type), opens after they arrive. Click or press any key to skip the moves.
• Faster, at the original's pace. Ship movement used to take nearly a second per square; it now follows SE4's own timings, about 1/20 of a second per square.
• Speed slider. A new "Ship movement speed" slider in Game Menu → Options, under "OpenSE4", goes from 1/8x to 8x. It also sets the speed of the movement replay.
• Movement lines on moving ships. While a ship moves, its blue movement line now shows the route it is following from the square it left, and it shrinks when the ship arrives.
  • As in SE4 on a fresh install, "Display Ship Movement Lines" starts off until you start a new game. Press Ctrl+L (or use Game Menu → Options) once and it stays on.

Window and files

• Hide the title bar. Settings → Graphics → "Hide the window's title bar" removes the system's title bar from the game's window. Drag the game's top row to move the window and its edges to resize it. The game's minimize button and Alt+Enter still work.
• Portable saves and settings.
  • Settings → Files → "Keep saves and settings in OpenSE4's folder" keeps your saves, settings and mods in a userdata folder next to the game, so the whole folder travels together. It offers to copy your files across and never deletes anything.
  • You can also put an empty portable.txt next to the program.
  • This needs the zip or tarball unpacked to a folder you can write to; the installer's Program Files copy can't do it (see PORTABLE-README.txt).
• Saves folder. Settings → Files also lets you choose a folder for your saved games.

Modding SDK documentation

• The documentation matches the SDK as released: the modder's guide, the SDK pages and the design document. The examples in the documentation are now checked by tests.
• Help texts: every program's --help describes what it really does.
• The shipped documents' links work in the downloads. They lead to the package's own copies, or to this release's files on GitHub.

Fixes

• opense4-datacheck --help prints its help instead of reading "--help" as a folder.
• Release builds of opense4-sdk no longer contain the path of the computer they were built on.

Compatibility

0.12.0 plays together with 0.11.0 over the network and by e-mail (protocol 7), and they read each other's saves (save format 9). It also loads saved games from 0.7.0 to 0.10.0. Every player in a network game must have the same game-changing mods.

Downloads

File	For
OpenSE4-0.12.0-windows-x86_64-setup.exe	64-bit Windows 7 SP1 to 11: the installer
OpenSE4-0.12.0-windows-x86_64.zip	64-bit Windows 7 SP1 to 11: the same programs to run from any folder
OpenSE4-0.12.0-linux-x86_64.tar.gz	64-bit Linux on PCs with glibc 2.34 or later (Ubuntu 22.04, Debian 12, Fedora 35, SteamOS 3 and newer)
OpenSE4-0.12.0-linux-aarch64.tar.gz	64-bit ARM Linux with glibc 2.34 or later (Raspberry Pi OS 64-bit, Asahi, Ubuntu and Debian on ARM)
OpenSE4-0.12.0-linux-armhf.tar.gz	32-bit ARM Linux (ARMv7 with NEON) with glibc 2.34 or later (Raspberry Pi OS 32-bit)
OpenSE4-0.12.0-SHA256SUMS.txt	SHA-256 checksums of the downloads

Every download holds five programs:

• the game (opense4);
• the dedicated server for network and play-by-e-mail games (opense4-server);
• a data checker (opense4-datacheck);
• the saved-game converter (opense4-convert);
• the modding tool (opense4-sdk).

It also holds the Hegemon mod (mods/; turn it on in the Mods window), the modder's documents and examples (sdk/) and, in the zip and tarballs, PORTABLE-README.txt. Libraries, our own fonts, the manual and the lessons are built in.

Running it

• Windows: run the installer, then start OpenSE4 from the Start menu, or unpack the zip and run opense4.exe. Neither is code-signed yet, so Windows SmartScreen may warn the first time ("More info", then "Run anyway").
• Linux, on a PC or on ARM: unpack and run ./opense4, or run ./install-desktop-entry.sh once to start it from your desktop's application list. On ARM boards without a Steam install, copy the game's files from another computer (see docs/SETUP.md).

The game looks for a Steam install of Space Empires IV Deluxe. See README.md for other locations and command-line options (opense4 --help). Modders start with sdk/docs/README.md.

Known limitations

• This is still an early build, marked as a pre-release.

• Not yet tested on real hardware:

  • Windows 7: only under Wine, with each program's imports checked against what Windows 7 provides.
  • ARM: only through emulation and native ARM test runners; the game window hasn't been opened on a real ARM graphics chip yet.

  Reports are welcome.

• Scripts run on MicroPython: in-game scripts use a built-in, sandboxed Python (MicroPython with additions), so libraries such as numpy are only available to external bots.

• Rules mods near their time limit: a rules mod that runs very close to its per-turn time limit could, rarely, replay a turn slightly differently.

• Hegemon rarely finishes off an empire within 150 turns; it wins by growing far ahead.

• Following warps: the view follows your ships through warp points in local, hotseat and e-mail games, but not yet for players who join someone else's network game.

• In network and e-mail games, every battle is resolved strategically, as in the original.

• The classic computer players hold slightly fewer colonies by turn 100 than the original's (about 15.8 against 17.0 per empire).

• Designs window: it doesn't yet remember which tab was open, as the original does.

License

OpenSE4 is free software under the GNU General Public License, version 3 or later. The Noto Sans fonts are under the SIL Open Font License. THIRD_PARTY_NOTICES.txt in each download lists the bundled libraries and their licences, among them MicroPython and miniz.

OpenSE4 0.11.0

OpenSE4 is an open-source engine for Space Empires IV Deluxe. It plays the classic game on your own installed copy of Space Empires IV Deluxe and contains nothing from the original game.

OpenSE4 is not affiliated with, endorsed by or sponsored by the game's publishers.

What changed since 0.10.0

This release opens OpenSE4 to modders. It also brings a new computer opponent, Hegemon, built with the new modding SDK.

Hegemon, a stronger computer opponent

Hegemon ships with OpenSE4 as a ready-to-use mod. Turn it on in the Mods window on the title screen, then choose it for computer empires in Game Setup or Quick Start. The classic computer players stay the default.

• Its own planning: Hegemon decides everything itself, with its own strategy, economy and expansion planning, research plan, ship designer, fleet operations, round-by-round battle tactics and diplomacy. It sees only what its own empire knows, like a human player.
• Against the classic computer players, at the same difficulty and bonuses, over 156 test games of 150 turns, it won 88% of them. That covers duels and 4- and 6-empire games, with simultaneous and turn-based turns.

If you want a harder game, give your opponents Hegemon.

The modding SDK

Everything a modder needs is in each download: the opense4-sdk tool, the modder's guide and reference in sdk/docs, and seven example mods in sdk/examples.

• Mods:
  • A mod is a folder or a .zip with a mod.toml.
  • Choose and order your mods in the new Mods window. Game Setup, Quick Start and the multiplayer lobby show which mods a game uses.
  • Mods are layered over your installed game, which is never changed. Classic mods made of replacement data files load too.
• Units and data: add, change or remove records in any data or AI table with patches, so several mods can be combined. New hulls and components come with their own pictures and sounds.
• Pictures and sounds: PNG with transparency, pictures larger than the classic size, OGG sound, and designs with a picture of their own.
• Computer players in Python:
  • A script player makes every decision the classic AI makes, battle rounds included, and keeps its own memory with the saved game.
  • Anything it leaves out plays exactly like the classic AI.
  • Choose each computer empire's player in setup or the lobby. An optional notes view (Ctrl+Shift+N) shows what a player is thinking.
• External bots and testing: bots can also run outside the game in regular Python with any library. The arena (opense4-sdk arena) plays many AI-against-AI games and reports the results.
• Rules scripts: Python hooks through the whole turn change the game through effects the engine checks. Mods can add their own orders, events, intelligence projects, game options, victory conditions, ability effects and scenarios.
• Interface: mods can add order buttons, panels in reports, columns in lists, pages in the Empires window, translations and key bindings.
• Safe and repeatable:
  • Scripts run in a sandbox with no access to your files, the network or the clock.
  • A failing script falls back to the classic AI and is reported in the game.
  • Games with scripts play out the same on every computer and platform.

Steam Workshop publishing waits for the Steam release; opense4-sdk pack already makes the package an upload would use.

Fixes

• Save Game: typing a name and then clicking Save, instead of pressing Enter, now keeps the typed name.

Compatibility

0.11.0 does not play with 0.10.0 or older over the network or by e-mail (protocol 7), so every player needs to update. It loads saved games from 0.7.0 to 0.10.0 (save format 9 now). Every player in a network game must have the same game-changing mods; the lobby says what differs.

Downloads

File	For
OpenSE4-0.11.0-windows-x86_64-setup.exe	64-bit Windows 7 SP1 to 11: the installer
OpenSE4-0.11.0-windows-x86_64.zip	64-bit Windows 7 SP1 to 11: the same programs to run from any folder
OpenSE4-0.11.0-linux-x86_64.tar.gz	64-bit Linux on PCs with glibc 2.34 or later (Ubuntu 22.04, Debian 12, Fedora 35, SteamOS 3 and newer)
OpenSE4-0.11.0-linux-aarch64.tar.gz	64-bit ARM Linux with glibc 2.34 or later (Raspberry Pi OS 64-bit, Asahi, Ubuntu and Debian on ARM)
OpenSE4-0.11.0-linux-armhf.tar.gz	32-bit ARM Linux (ARMv7 with NEON) with glibc 2.34 or later (Raspberry Pi OS 32-bit)
OpenSE4-0.11.0-SHA256SUMS.txt	SHA-256 checksums of the downloads

Every download holds five programs:

• the game (opense4);
• the dedicated server for network and play-by-e-mail games (opense4-server);
• a data checker (opense4-datacheck);
• the saved-game converter (opense4-convert);
• the modding tool (opense4-sdk).

It also holds the Hegemon mod (mods/) and the modder's documents and examples (sdk/). Libraries, our own fonts, the manual and the lessons are built in.

Running it

• Windows: run the installer, then start OpenSE4 from the Start menu, or unpack the zip and run opense4.exe. Neither is code-signed yet, so Windows SmartScreen may warn the first time ("More info", then "Run anyway").
• Linux, on a PC or on ARM: unpack and run ./opense4, or run ./install-desktop-entry.sh once to start it from your desktop's application list. On ARM boards without a Steam install, copy the game's files from another computer (see docs/SETUP.md).

The game looks for a Steam install of Space Empires IV Deluxe. See README.md for other locations and command-line options (opense4 --help). Modders start with sdk/docs/README.md.

Known limitations

• This is still an early build, marked as a pre-release.

• Not yet tested on real hardware:

  • Windows 7: only under Wine, with each program's imports checked against what Windows 7 provides.
  • ARM: only through emulation and native ARM test runners; the game window hasn't been opened on a real ARM graphics chip yet.

  Reports are welcome.

• Scripts run on MicroPython: in-game scripts use a built-in, sandboxed Python (MicroPython with additions), so libraries such as numpy are only available to external bots.

• Rules mods near their time limit: a rules mod that runs very close to its per-turn time limit could, rarely, replay a turn slightly differently.

• Hegemon rarely finishes off an empire within 150 turns; it wins by growing far ahead.

• Following warps: the view follows your ships through warp points in local, hotseat and e-mail games, but not yet for players who join someone else's network game.

• In network and e-mail games, every battle is resolved strategically, as in the original.

• The classic computer players hold slightly fewer colonies by turn 100 than the original's (about 15.8 against 17.0 per empire).

• Designs window: it doesn't yet remember which tab was open, as the original does.

License

OpenSE4 is free software under the GNU General Public License, version 3 or later. The Noto Sans fonts are under the SIL Open Font License. THIRD_PARTY_NOTICES.txt in each download lists the bundled libraries and their licences, among them MicroPython and miniz.

OpenSE4 0.10.0

OpenSE4 is an open-source engine for Space Empires IV Deluxe. It plays the classic game on your own installed copy of Space Empires IV Deluxe and contains nothing from the original game.

OpenSE4 is not affiliated with, endorsed by or sponsored by the game's publishers.

What changed since 0.9.0

Thank you to everyone who played 0.9.0 and reported problems here and on Discord. This release fixes every open report, and lets your games move between OpenSE4 and the original.

Your games from the original

• Load an original saved game. Load Game opens the original's .gam files (version 1.95) and converts them as they load. Use Change Directory to open the original's SaveGame folder, or start with opense4 --load=PATH/GAME.gam. A note lists anything that came across only approximately.
• Save a game for the original. Save Game has a new Save for SE IV button. It writes the game in the original's format, with the players' History files beside it. Copy them into the original's SaveGame folder to play on there.
• Checked in the original: the converted games load in the original and play on. Players sign in to multiplayer games, the Log lists its entries, and ships keep their orders.
• What doesn't carry over:
  • partial damage to a ship's parts (the original stores each part only as destroyed or intact);
  • the random sequence: the next turn won't roll the same dice;
  • diplomatic messages not yet delivered;
  • part of the computer players' memory, on import;
  • passwords, on export.
• Same data files on both sides: the original only accepts a game made with the same data files as its install, so a modded game needs the same mod there.
• Command line: opense4-convert converts in both directions and describes a saved game of the original. It is included in every download.

Sound

• Muted in the background: the music and sound effects go quiet while the game is minimized or another window has the focus, and come back when you return. You can turn this off in Options ("Mute when the game is in the background").

Fixes from your reports

• Upgrade on the Designs page (#5): each part is replaced by the newest part of its line that you have researched, as in the original. Ion Engine III now becomes Contra-Terrene Engine I once you have it, instead of the other way round. Upgrade always opens the designer, as the original does.

• Ships ordered together (#7): in turn-based games, ships you shift-select and give one order now move as one group and fight one battle, as in the original. If the trip takes more than a turn, they carry on separately from the next turn, as they do in the original; a fleet keeps them together.

• Fleets in the sector list (#8): each of your fleets is one row, as in the original. Clicking it opens the Fleet Report. In its list of ships, a left-click makes a ship the fleet leader and a right-click opens its report.

• Hide Obsolete (#1): Hide Obsolete and Stats\Strategy in the Designs window are kept with your empire and in saved games, as in the original.

• System picture (#2): the system's picture no longer covers the top bar of the sector details pane.

• Scores and Treaty Grid (#3): both windows fit everything:

  • ten empires to a page;
  • each column headed by the empire's flag and the start of its name (hover for the full name);
  • Scores now has one column per empire, so every figure shows in full.

• Inbox notice (#4): "Inbox: 1 waiting" only counts messages you can still answer from the Log, so it clears once the chance to reply has passed.

• Construction progress over 100% (#6): the progress figure counts each resource only up to what the item needs, so it stays under 100% until the item is built. Building itself was always right.

• Error box in the Log (#9): the Log's details pane no longer causes a developer error box for entries without text, such as retrofits. Release builds never show these boxes; they are written to opense4.log instead.

• Combat entries in the Log (#10): we could not make a battle entry go missing in about 1,500 test battles. Two things that could hide entries are fixed:

  • the error box from #9, which covered the list;
  • the Log reopening part way down a new turn's list.

  If you still miss one, please attach a save from just before the battle.

Compatibility

0.10.0 does not play with 0.9.0 or older over the network or by e-mail (protocol 6), so every player needs to update. It loads saved games from 0.7.0 to 0.9.0 (save format 8 now; 7 still reads).

Downloads

File	For
OpenSE4-0.10.0-windows-x86_64-setup.exe	64-bit Windows 7 SP1 to 11: the installer
OpenSE4-0.10.0-windows-x86_64.zip	64-bit Windows 7 SP1 to 11: the same programs to run from any folder
OpenSE4-0.10.0-linux-x86_64.tar.gz	64-bit Linux on PCs with glibc 2.34 or later (Ubuntu 22.04, Debian 12, Fedora 35, SteamOS 3 and newer)
OpenSE4-0.10.0-linux-aarch64.tar.gz	64-bit ARM Linux with glibc 2.34 or later (Raspberry Pi OS 64-bit, Asahi, Ubuntu and Debian on ARM)
OpenSE4-0.10.0-linux-armhf.tar.gz	32-bit ARM Linux (ARMv7 with NEON) with glibc 2.34 or later (Raspberry Pi OS 32-bit)
OpenSE4-0.10.0-SHA256SUMS.txt	SHA-256 checksums of the downloads

Every download holds four programs:

• the game (opense4);
• the dedicated server for network and play-by-e-mail games (opense4-server);
• a data checker (opense4-datacheck);
• the saved-game converter (opense4-convert).

Libraries, our own fonts, the manual and the lessons are built in.

Running it

• Windows: run the installer, then start OpenSE4 from the Start menu, or unpack the zip and run opense4.exe. Neither is code-signed yet, so Windows SmartScreen may warn the first time ("More info", then "Run anyway").
• Linux, on a PC or on ARM: unpack and run ./opense4, or run ./install-desktop-entry.sh once to start it from your desktop's application list. On ARM boards without a Steam install, copy the game's files from another computer (see docs/SETUP.md).

The game looks for a Steam install of Space Empires IV Deluxe. See README.md for other locations and command-line options (opense4 --help).

Known limitations

• This is still an early build, marked as a pre-release.

• Not yet tested on real hardware:

  • Windows 7: only under Wine, with each program's imports checked against what Windows 7 provides.
  • ARM: only through emulation and native ARM test runners; the game window hasn't been opened on a real ARM graphics chip yet.

  Reports are welcome.

• Following warps: the view follows your ships through warp points in local, hotseat and e-mail games, but not yet for players who join someone else's network game.

• Computer players hold slightly fewer colonies by turn 100 than the original's (about 15.8 against 17.0 per empire).

• In network and e-mail games, every battle is resolved strategically, as in the original.

• Designs window: it doesn't yet remember which tab was open, as the original does.

License

OpenSE4 is free software under the GNU General Public License, version 3 or later. The Noto Sans fonts are under the SIL Open Font License. THIRD_PARTY_NOTICES.txt in each download lists the bundled libraries and their licences.

OpenSE4 0.9.0

OpenSE4 is an open-source engine for Space Empires IV Deluxe. It plays the classic game on your own installed copy of Space Empires IV Deluxe and contains nothing from the original game.

OpenSE4 is not affiliated with, endorsed by or sponsored by the game's publishers.

What changed since 0.8.1

Thank you to everyone who tried 0.8.1 and reported problems. This release fixes them, and brings the game to more computers.

More systems

• Windows 7 SP1 to Windows 11 from one download. The Windows build now uses the C runtime every Windows 7 SP1 machine already has, so nothing extra needs installing. The installer explains when Windows is too old. Folder names with accented or non-Latin letters now work on Windows 7 to 8.1 too.
• ARM Linux, 64-bit (aarch64) and 32-bit (armhf, ARMv7 with NEON). These packages need glibc 2.34 or newer (Debian 12, Ubuntu 22.04, Raspberry Pi OS 12).
  • Machines that can run the game: Raspberry Pi 4 and 5 on current Raspberry Pi OS, recent RK3588 boards, Apple Silicon under Asahi Linux, and Snapdragon laptops. The game needs Vulkan 1.3 or OpenGL 3.3.
  • Older boards such as the Pi 3 can't draw the game, but they can host the dedicated server.
  • Games on ARM play exactly like games on PCs, so everyone can play together.

Fixes from your reports

• Crash after a battle: choosing Strategic when an enemy arrived through a warp point could crash the game.
• Turns are safer: an error during a turn can no longer advance the game or save half a turn. A second End Turn click, or Enter, pressed while a turn is still processing no longer ends the next turn too.
• Crash reports: if OpenSE4 ever crashes, it writes a report to opense4.log and tells you where to find it. Please send that file with any crash report.
• Windows over windows: while a window or a question is open, the main screen no longer takes clicks or keys. End Turn can't be pressed during a battle or while designing a ship.
• Music and sound:
  • Music keeps playing instead of stopping after its first track.
  • The random popping is gone: sounds and tracks now fade instead of being cut off mid-wave, and the mix no longer clips.
  • opense4.log says which music it found and why a file couldn't play.
• Race Report: it is now a proper report window, with its tabs and a Close button. It closes together with the Empires window.
• Black holes: system reports, black holes included, wrap and scroll instead of cutting off their text.
• Stray lines under warp points and asteroid fields are gone.
• Text size: at larger text sizes, text no longer spills out of buttons or over other text.

Closer to the original game

• Colonizing moons: when a sector holds several planets or moons, a window asks which one to colonize, as in the original. Warp, Drop Cargo and Attack use the same picker.
• Log pictures: every entry in the Log shows its picture again.
• Following your ships: in turn-based games the view follows your ships through warp points while their orders run.
• Keeping your selection: looking at another system keeps your selected ship, its report and its orders.
• Right-click reports: the owner box at the top of Set Construction Queue opens the planet's report, and a facility or component on the Facil and Comps tabs opens its report.
• Ability tab: shows one readable line per ability, as the original does.
• Report tabs: go back to Detail for each new selection.
• Moving population: you can move it between your colonies in the same sector with Cargo Transfer.
• Sector marks: a sector marks only the planet it shows, with either a colony box or a colonizable star.
• Only Latest: in the designer and the build queue, Only Latest keeps only the newest of each line (a new Contra-Terrene engine hides Ion Engine III).
• Hidden planets: you can't colonize a planet your empire can't currently see, as in the original. This matters only in modded or unusual situations; normal galaxies never start with one.

Compatibility

0.9.0 plays together with 0.7.0, 0.8.0 and 0.8.1 over the network and by e-mail (protocol 5), and they read each other's saves (save format 7).

Downloads

File	For
OpenSE4-0.9.0-windows-x86_64-setup.exe	64-bit Windows 7 SP1 to 11: the installer
OpenSE4-0.9.0-windows-x86_64.zip	64-bit Windows 7 SP1 to 11: the same programs to run from any folder
OpenSE4-0.9.0-linux-x86_64.tar.gz	64-bit Linux on PCs with glibc 2.34 or later (Ubuntu 22.04, Debian 12, Fedora 35, SteamOS 3 and newer)
OpenSE4-0.9.0-linux-aarch64.tar.gz	64-bit ARM Linux with glibc 2.34 or later (Raspberry Pi OS 64-bit, Asahi, Ubuntu and Debian on ARM)
OpenSE4-0.9.0-linux-armhf.tar.gz	32-bit ARM Linux (ARMv7 with NEON) with glibc 2.34 or later (Raspberry Pi OS 32-bit)
OpenSE4-0.9.0-SHA256SUMS.txt	SHA-256 checksums of the downloads

Every download holds three programs:

• the game (opense4);
• the dedicated server for network and play-by-e-mail games (opense4-server);
• a data checker (opense4-datacheck).

Libraries, our own fonts, the manual and the lessons are built in.

Running it

• Windows: run the installer, then start OpenSE4 from the Start menu, or unpack the zip and run opense4.exe. Neither is code-signed yet, so Windows SmartScreen may warn the first time ("More info", then "Run anyway").
• Linux, on a PC or on ARM: unpack and run ./opense4, or run ./install-desktop-entry.sh once to start it from your desktop's application list. On ARM boards without a Steam install, copy the game's files from another computer (see docs/SETUP.md).

The game looks for a Steam install of Space Empires IV Deluxe. See README.md for other locations and command-line options (opense4 --help).

Known limitations

• This is still an early build, marked as a pre-release.

• Not yet tested on real hardware:

  • Windows 7: only under Wine, with each program's imports checked against what Windows 7 provides.
  • ARM: only through emulation and native ARM test runners; the game window hasn't been opened on a real ARM graphics chip yet.

  Reports are welcome.

• Following warps: the view follows your ships through warp points in local, hotseat and e-mail games, but not yet for players who join someone else's network game.

• Computer players hold slightly fewer colonies by turn 100 than the original's (about 15.8 against 17.0 per empire).

• In network and e-mail games, every battle is resolved strategically, as in the original.

License

OpenSE4 is free software under the GNU General Public License, version 3 or later. The Noto Sans fonts are under the SIL Open Font License. THIRD_PARTY_NOTICES.txt in each download lists the bundled libraries and their licences.

OpenSE4 0.8.1

OpenSE4 is an open-source engine for Space Empires IV Deluxe. It plays the classic game on your own installed copy of Space Empires IV Deluxe and contains nothing from the original game.

OpenSE4 is not affiliated with, endorsed by or sponsored by the game's publishers.

What changed since 0.8.0

Every tutorial step was audited at both screen layouts, then attacked by a tester over three rounds. Each step now accepts only the action its text asks for, keeps what it points at in view, and can always be finished.

Only the right choice

• Choosers allow exactly the option the step names. The others are dimmed and refused:
  • Designing: Ship rather than Base when creating a design, the hull, the design type.
  • Building: the design's row in the build queue.
  • Combat Simulator: the race and the items.
  • Communicate: the message type and the treaty.
  • Other choices: the colony type, the intelligence project.
• Orders go to the right ship. The ship arrows are locked while a step gives an order.
• Windows left open by earlier steps answer only to Close. That covers windows such as the Galaxy Map, Strategies and the Log, which used to be fully usable.
• Esc and Enter reach only the window in front. They can no longer throw away a design, empty the simulator, or end the turn from behind another window.
• Right-clicks in the main window work only where a step allows them, so they can't give a Move To order or open the Galaxy Map unasked. Inside windows they still show reports and pan maps.
• Keyboard navigation is off while a tutorial locks the game. Tab, Space and Enter can't press a hidden button, and Ctrl+Tab can't leave a text field.
• A double-click on Next moves one step.
• Steps check what was really done. A treaty proposal must be the named treaty, not a General Message. The fleet must be sent somewhere it actually has to travel.

Everything a step points at is in view

• New show areas: parts a step asks you to read, such as the design details, Warnings, the queues, Combat Vehicles and the Log's details, are no longer dimmed. The lesson panel keeps clear of them.
• The lesson panel also keeps clear of the dashed way-back button and of the lists a step refers to at 800×600.
• Set Construction Queue always shows each design's type, shortening long names.
• Text matches the screen.
  • "Fleets, movement and supply" asks you to press Ctrl+L before it describes the route line.
  • The Select Waypoint window's labels no longer overlap its title.
  • The pick prompt doesn't offer Esc while a lesson locks the game.

Never stuck

• Going back a step. If you close the ship designer, the Combat Simulator or Communicate while working in it (only possible with Free Play), their unsaved work is gone. The lesson then goes back to the step that sets it up again and says why.
• Other windows keep your place. The button that reopens them is outlined.
• Tested everywhere. This was tried in 31 places at both layouts; every lesson could still be finished.

Tools

• python3 tools/check_lessons.py --audit checks every tutorial step at both layouts. It reports choices that would let a wrong click through, and parts the text names that are dimmed, off screen or under the panel.
• Regression scripts: new input scripts try the wrong clicks found here and expect them to be refused. There are 82 runs at both layouts.
• README screenshots: the project page now shows the game in action.

Compatibility

0.8.1 plays together with 0.7.0 and 0.8.0 over the network and by e-mail (protocol 5), and they read each other's saves (save format 7).

Downloads

File	For
OpenSE4-0.8.1-windows-x86_64-setup.exe	64-bit Windows 10 and 11: the installer
OpenSE4-0.8.1-windows-x86_64.zip	64-bit Windows 10 and 11: the same programs to run from any folder
OpenSE4-0.8.1-linux-x86_64.tar.gz	64-bit Linux with glibc 2.34 or later (Ubuntu 22.04, Debian 12, Fedora 35, RHEL 9, SteamOS 3 and newer)
OpenSE4-0.8.1-SHA256SUMS.txt	SHA-256 checksums of the three downloads

Every download holds three programs:

• the game (opense4);
• the dedicated server for network and play-by-e-mail games (opense4-server);
• a data checker (opense4-datacheck).

Libraries, our own fonts, the manual and the lessons are built in. The game needs a GPU with Vulkan or OpenGL 3.3.

Running it

• Windows: run the installer, then start OpenSE4 from the Start menu, or unpack the zip and run opense4.exe. Neither is code-signed yet, so Windows SmartScreen may warn the first time ("More info", then "Run anyway").
• Linux: unpack and run ./opense4, or run ./install-desktop-entry.sh once to start it from your desktop's application list.

The game looks for a Steam install of Space Empires IV Deluxe. See README.md for other locations and command-line options (opense4 --help).

Known limitations

• This is still an early build, marked as a pre-release.
• Computer players hold slightly fewer colonies by turn 100 than the original's (about 15.7 against 17.0 per empire). This is still being investigated.
• Windows builds are tested in CI and under Wine. The executables aren't code-signed.
• In network and e-mail games, every battle is resolved strategically, as in the original.

License

OpenSE4 is free software under the GNU General Public License, version 3 or later. The Noto Sans fonts are under the SIL Open Font License. THIRD_PARTY_NOTICES.txt in each download lists the bundled libraries and their licences.