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.

OpenSE4 0.8.0

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 0.7.0

This release reworks the guided tutorials after a top-to-bottom review of how they feel to a new player.

Guidance that can't be lost

• Steps check the right ship. A step that asks for an attack ship now waits for one. In "Exploring and colonizing" the colony ship is sent out before anything explores, so a stray click can no longer send it exploring and leave the lesson impossible to finish.
• The lock follows the window in front. Only what the step points at responds, even when one window sits on top of another (the ship designer over Designs, Set Queue over the queues, the simulator over Designs).
• A way back instead of Skip. If you close a window the step needs, the button that reopens it gets a dashed cyan outline, and the panel says what to press ("Press the Designs button (F3), then Create"). If a window covers the outlined part, its Close button is pointed out.
• Skip only when there is truly no way back. It appears after 10 seconds, never during steps that simply take a few turns, and skipping no longer cascades into the next step.
• Questions keep their keys. Answering a lesson question with N or Enter no longer also fires a main-window shortcut.
• The End Turn question comes to the front. It no longer opens behind an open window.
• Calmer feedback. A refused click first says "Click the pulsing yellow outline". Free Play is offered only after a few refused clicks, and it is switched off whenever a lesson starts.
• A steadier outline. It never fades below 55%, has a dark edge so it stands out from the game's own frames, and flashes at most twice a second.

A lesson panel that stays out of the way

• Never over a question. The panel stays under the game's prompts and pop-ups and places itself clear of them, so at 800×600 OK and Colonize can always be clicked.

• Follows the text size. The panel sizes itself from Settings → Graphics → Text size, and its buttons flow into rows that never overlap.

• Compact at 800×600. Action steps show a compact panel with a More button, so the window being taught stays visible.

• Keys for the panel:

  • Alt+N (Next);
  • Alt+B (Back);
  • Alt+K (Skip, when offered);
  • Alt+R (Read More).

  You can change them in Settings → Controls. Shift+F1 opens the manual during a lesson too.

• Order strip pages at 800×600. When the outlined order is on another page of the order strip, the panel says so and points at the arrow.

Shorter, clearer lessons

• Every step starts with what to do, in bold, then a short reason.
• Much less to read. Steps average 39 words instead of 48, the longest has 59, and nothing needs scrolling at 1024×768.
• Your own design names. Lessons show the names your designs carry ("click Aaóuane twice"), and the simulator and build lists show each design's type.
• Lists show the row you need. When a step names one of your designs, Set Queue and the Combat Simulator scroll it into view.
• Progress lines. Steps that wait on the game say how far along you are ("Systems explored: 3 of 5", "Turns: 1 of 3").
• Content fixes:
  • Ctrl+L explained correctly;
  • the Log that opens by itself explained;
  • a design-type step in "Designing ships";
  • "close the window, then End Turn";
  • a step that finished instantly removed.

Finishing and coming back

• A richer result. It recaps what you practised and names the next lesson. After the last tutorial it suggests the Land Rush training game.
• The Learn window points you onward. It counts "N of 7 done" and marks the next lesson.
• Resume where you left. The Learn window offers "Resume (step N)" for a tutorial you left unfinished.
• A start-here hint. First-time players see a hint at the intro's Tutorial button.

Testing

• Input scripts at both sizes. The scripts play every tutorial through at both 1024×768 and 800×600 (tools/run_input_tests.py --small). New scripts cover the lock with stacked windows, the way back, Skip, prompts and the panel.
• CI plays the fixture-data scripts at both sizes.

Compatibility

0.8.0 plays together with 0.7.0 over the network and by e-mail (both use protocol 5), and they read each other's saves (save format 7). It doesn't play with 0.6 or earlier.

Downloads

File	For
OpenSE4-0.8.0-windows-x86_64-setup.exe	64-bit Windows 10 and 11: the installer
OpenSE4-0.8.0-windows-x86_64.zip	64-bit Windows 10 and 11: the same programs to run from any folder
OpenSE4-0.8.0-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)
OpenSE4-0.8.0-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.

OpenSE4 0.7.0

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 0.6.1

Network and play-by-e-mail games

• Encrypted connections.
  • Every network game is encrypted.
  • The game remembers each host's key and refuses an impostor. If a host's key changes, you see both fingerprints and must confirm twice.
  • A join password is built into the encryption itself.
• Passwords never travel.
  • Empire and join passwords are turned into keys with a slow, salted hash (Argon2id), so a captured login can't be replayed and guessing is expensive.
  • Reset Passwords now gives 12 digits instead of 6.
• Private e-mail turn files.
  • Each player gets a turn file with only their own view of the game, encrypted for them and signed by the host.
  • Orders files are signed and encrypted for the host.
  • Other players can't read your turn in a shared folder, and a forged turn file is refused.
• Reconnects.
  • A player whose connection drops mid-turn reconnects and carries on.
  • Orders and commands that got no answer are sent again, and nothing is carried out twice.
• Desyncs are caught and repaired.
  • If a player's copy of the game drifts from the host's, both see which turn and which part of the game differed.
  • The player's copy is repaired from the host's state, and the event is written to opense4.log.
• Random seeds. Hosted games now draw the galaxy seed from the system's secure random source, so the map can't be worked out from the start time.
• Server options. opense4-server --no-password-migration refuses to move OpenSE4 0.6 passwords automatically, and password-verifier prepares a password for a setup file.

Windows in the original's layouts

• Setup. Game Setup, Empire Setup, Quick Start and Load Game look and work as in the original.
  • Empire Setup gains an e-mail box, and Change Email in Empire Status works.
  • Quick Start lists the races in the original's order, eight to a page.
• Every list has the original's scroll arrows and a thumb.
• Management windows. Research, Intelligence, Empire Status, Colonies, Designs, Create Design, Help and the Galaxy Map follow the original's positions.
  • Borders is a window of its own.
  • The Weapons Report export writes the original's four files.
• Battle windows.
  • Tactical Combat and the Combat Piece Report sit at the original's positions.
  • Combat Replay uses the Tactical Combat frame, and its Options use check boxes.
  • Ground Combat shows the original's grids.
• Endings appear as they happen: a defeated player sees Lose, then Human Dead. Conquering the galaxy offers to keep playing.
• Players window.
  • Neutral empires can be handed to and from computer control.
  • A network host can switch any empire.

Rules and computer players

• New games use the original's defaults: random computer and neutral players, Catastrophic events at most, and the original's victory values. Quick Start rolls its opponents as the original does.
• Home systems are spread exactly as the original spreads them. This came out of a comparison of 544 of the original's galaxies with ours, which agreed on every other measure.
• Computer players defend and attack like the original's.
  • When threatened, they send only nearby defence fleets and keep their attack fleets back.
  • They build their first ships in the original's order.
  • Idle ships can start battles.
  • They measure distances the way the original does.
  • They now lose and take colonies at close to the original's rate, and their early ships come on the same turns.

Testing

• Input scripts. opense4 --input-script=FILE plays scripted clicks and keys through the game's real input, and --record-input writes a script from a session you play.
  • 23 scripts play every tutorial end to end under the tutorial lock, the training games, the manual and the mouse-only features.
  • They found and fixed Esc and Enter not closing windows in tutorials, three tutorial steps that couldn't be completed, and list arrows that drifted.

Compatibility

0.7.0 does not play with 0.6.x (network protocol 5 instead of 4), and 0.6 saves can't be loaded (save format 7). Both players need 0.7.0. Releases that share protocol 5 play together.

Games moving from 0.6 to 0.7:

• Network: each player confirms the host's key once before their old password is upgraded.
• Play by e-mail: the host runs opense4-server pbem turn-files once, and each player chooses a new password on their next turn.

Downloads

File	For
OpenSE4-0.7.0-windows-x86_64-setup.exe	64-bit Windows 10 and 11: the installer
OpenSE4-0.7.0-windows-x86_64.zip	64-bit Windows 10 and 11: the same programs to run from any folder
OpenSE4-0.7.0-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)
OpenSE4-0.7.0-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 follows how many enemy colonies sit inside their territories, which 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, including Monocypher (BSD-2-Clause / CC0) for the encryption.

OpenSE4 0.6.1

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 0.6.0

A maintenance release. The game plays exactly as 0.6.0 does.

• Build fix: OpenSE4 builds without warnings with Visual Studio 2022 again. Players are not affected: the downloads are built with MinGW, which 0.6.0 also used.
• Docs: the multiplayer documentation now gives the network protocol's version history correctly.

0.6.1 and 0.6.0 play together over the network and by e-mail (both use protocol 4), and they read each other's saves (save format 6). Saves from 0.5.0 and earlier can't be loaded.

For everything new in the 0.6 series, see the 0.6.0 release notes: computer players brought closer to the original's fleets, budget, scrapping and base building.

Downloads

File	For
OpenSE4-0.6.1-windows-x86_64-setup.exe	64-bit Windows 10 and 11: the installer
OpenSE4-0.6.1-windows-x86_64.zip	64-bit Windows 10 and 11: the same programs to run from any folder
OpenSE4-0.6.1-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)
OpenSE4-0.6.1-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

As in 0.6.0:

• This is still an early build, marked as a pre-release.
• Smaller differences in how the computer players play are still being measured. They fight more decided battles away from colonies, take fewer enemy colonies, and have about one ship fewer at turn 50. They also explore a little less in the first 25 turns.
• 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.

OpenSE4 0.6.0

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 0.5.0

This release brings the computer players closer to the original's. The original game was watched under a read-only debugger over seven 100-turn games: every empire's state, battles and base placements, recorded turn by turn. The rules found there are now in OpenSE4.

• Fleets and movement.
  • The ministers' movement orders now last one turn, as in the original, so warships are free for new tasks each turn.
  • Ships recruited into a fleet chase it until they join.
  • Fleets are no longer formed around troop transports or empty carriers.
• Targets and exploration follow the original's rules: which enemy planets are worth attacking, and which ships go exploring.
• Budget and scrapping.
  • The construction budget accounts for what the queues are already spending.
  • Colony ships no longer count toward the maintenance limit.
  • Over the limit, the computers scrap their oldest ship design, as the original does. They used to scrap their bases first.
  • So computer players now keep their bases, and found more colonies.
• Combat: a piece blocked by an obstacle now tries to slide around it, as in the original.
• Saves: like the original, a saved game no longer keeps the mood changes waiting for the next turn.

Compared with the original's computer players over 100 turns:

• the time they spend in their short-term defence state, and their research per colony, now fall within the original's spread from game to game;
• bases per empire went from about 0.1 to about 0.35 (the original: 0.4–0.6 in most games).

Saved games from earlier versions can't be loaded (save format 6), and every player in a network game needs 0.6.0 (protocol 4).

Downloads

File	For
OpenSE4-0.6.0-windows-x86_64-setup.exe	64-bit Windows 10 and 11: the installer
OpenSE4-0.6.0-windows-x86_64.zip	64-bit Windows 10 and 11: the same programs to run from any folder
OpenSE4-0.6.0-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)
OpenSE4-0.6.0-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.
• Smaller differences in how the computer players play are still being measured. They fight more decided battles away from colonies, take fewer enemy colonies, and have about one ship fewer at turn 50. They also explore a little less in the first 25 turns.
• 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.

OpenSE4 0.5.0

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 0.4.0

Same game on every computer

• Linux and Windows now give identical results and pictures. A new test plays fixed 100-turn games and battles and checks the exact final state. Continuous integration runs it on Linux (GCC and Clang), Windows (Visual Studio 2022 and 2026, MinGW) and macOS, and every build must agree.
• Fixed on Windows:
  • At 125 % or 150 % display scaling, the classic text was drawn too large and overflowed its buttons.
  • A minimized game stopped talking to the host and was dropped from network games.
  • Installs or profiles in folders with non-English letters lost their art and music.
  • The Steam library on another drive is now found.
• Fixed on Linux: the game's files are now found whatever the case of their names, and AltGr no longer triggers shortcuts.

Closer to the original

• Movement lines look like the original's: a blue route following the ship's real path, with a ring and the turns needed at each point. A new simultaneous game (Quick Start, setup or hosting) turns them on. Ctrl+L shows or hides them, which a player joining someone else's game may need.
• No starting ships. New games start without ships or designs, as the original's do.
  • Quick Start gives your empire the original's eleven prototype designs.
  • Computer players design their own on the first turn.
• The Scrap window's Analyze and Fire On work, and every Scrap action follows the original's turn rules.
  • Analyze destroys one of your ships at your space yard in return for tech levels.
  • Fire On has your armed ships destroy a vehicle of yours.
• Player Computer Control: you can hand any empire to the computer or take it back. A local game ends when no human is left.
• Reset Passwords is available on the host of a simultaneous game.
• Cloaked colonies you haven't detected are no longer drawn, selectable, or sent to other players' computers.
• Rules:
  • first contact happens at the original's moments;
  • Drop Troops refusals and planets dropping troops follow the original;
  • trades are logged item by item;
  • Save Empire keeps strategies;
  • computer players follow more of the original's rules: the exploration frontier, territory, colonization danger and queue choices.
• Animation:
  • ships turn and slide frame by frame;
  • combat animations use timings measured on the original;
  • Strategic Combat runs at the original's speed;
  • the selected sector uses the original's marker.
• Windows laid out as the original's:
  • lists with arrow buttons and "Pic" headings, and check boxes where the original has them;
  • Planets, Colonies, Research (completed areas stay listed), Designs (grouped by type, with a component grid);
  • Create Design (which asks for the vehicle type first);
  • Empire Status, Empires, Ships\Units, the Combat Simulator and Tactical Combat;
  • the list windows sort as the original's do.
• Settings.txt keys that were ignored now work: music on or off, exporting weapon and component data, the ship movement delay, and the ending pictures.

Learning

• Tutorials guide every action. During a tutorial step only the controls it teaches respond; everything else is dimmed. The step moves on once you've done what it asks. Free Play in the lesson panel unlocks the game, and Skip appears if a step can no longer be done.
• The lessons and manual are updated for games that start without ships and for the new window layouts.

Saved games from earlier versions can't be loaded (save format 5), and every player in a network game needs 0.5.0 (protocol 3).

Downloads

File	For
OpenSE4-0.5.0-windows-x86_64-setup.exe	64-bit Windows 10 and 11: the installer
OpenSE4-0.5.0-windows-x86_64.zip	64-bit Windows 10 and 11: the same programs to run from any folder
OpenSE4-0.5.0-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)
OpenSE4-0.5.0-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 fall behind the original's after about turn 25. They:
  • spend too long in their short-term defence state;
  • get less research out of each colony;
  • build almost no bases.
    This is being investigated against the original.
• 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.

OpenSE4 0.4.0

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 0.3.0

Combat

• Battles are shown as they are fought. A battle with one of your ships now stops before the first combat turn and is fought step by step while the Strategic Combat window shows it. Reports and log entries follow when you close it. The result is exactly the same whether or not the battle is shown.
• Ground combat round by round. The Ground Combat window plays every round with the unit counts after each. It also opens for the fight at the end of the colony owner's turn.
• Drop Troops checks no treaty, as in the original. Troops land on the last adjacent colony of another empire, and can take an ally's colony.
• Combat windows: the Combat Piece Report, the Tactical Orders pickers and Fast Tactical Combat now match the original.
• Combat Simulator: it now opens the real Fleet Transfer and Cargo Transfer windows.
• Computer pieces: drone targeting, firing range and the battle verdict now follow the original.

Colonies and orders

• Colony cloaking. Colonies with cloaking facilities can cloak. This affects detection, combat, intelligence and the computer players. A cloaked colony keeps building, but its space yard stops working.
• New orders:
  • Jettison Cargo drops cargo at once.
  • Convert Resources turns one resource into another at the colony's conversion rate.
  • Use Facility is now available, and Use Component now behaves as in the original.
• Fleets and stellar manipulation: further details now follow the original. Examples are mothballed fleet members, and objects that stellar manipulation replaces.

Looks

• The original's fonts and pointers, read from your install, with the original's text and button colours.
• The 800×600 layout. It is chosen on small desktops, as the original does. You can also force either layout in Settings, or with --layout=800x600 or --layout=1024x768.
• Main window:
  • The system view draws owner flags, counts, cloak markers and facility markers as the original does.
  • The Log, the Planets and Construction Queues windows, and the confirmations follow the original too.
• Movement replay. In a simultaneous game, the movement buttons replay the turn's real 30 days.

Under the hood

• Continuous integration. Every change is now built and tested on Linux (GCC, Clang, and the address and undefined-behaviour sanitizers) and on real Windows (Visual Studio and MinGW), including an install and uninstall test of the installer.
• Fixed: battle placement could differ between builds made with different compilers. This mattered for network games between, for example, Windows and Linux players.

Saved games from earlier versions can't be loaded (save format 4).

Downloads

File	For
OpenSE4-0.4.0-windows-x86_64-setup.exe	64-bit Windows 10 and 11: the installer
OpenSE4-0.4.0-windows-x86_64.zip	64-bit Windows 10 and 11: the same programs to run from any folder
OpenSE4-0.4.0-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)
OpenSE4-0.4.0-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. You can also 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). The title screen's Tutorial button and the in-game manual help you get started.

Known limitations

• This is still an early build, marked as a pre-release.
• The Windows build is tested on real Windows in CI. Our tests can't run the full game there, because that needs the original game data.
• The lessons haven't been played through by hand yet.
• 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 0.3.0

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 0.2.1

Learn to play

• Tutorials: seven guided lessons take you from your first turn to colonizing, research and construction, ship design, fleets and movement, combat, and diplomacy and intelligence. Each step outlines the button or window it is about and waits until you have done it.
• Training games: five practice games with objectives, briefings, hints and deadlines: a land rush, a research sprint, a fortress, a conquest and a diplomat.
• An in-game manual in 24 chapters, with contents, search, and links that open the game's windows. Press Shift+F1 for the page about the window in front. If your install has the original's manual, a button opens it in your browser.
• Open them from the title screen's Tutorial and Scenario buttons, from Manual, or from Learn in the Game Menu. During a lesson, Ctrl+H or the T button in the status bar brings the lesson panel back.

All lessons and the manual are our own writing.

Closer to the original

Every remaining question about the original's rules and interface was settled from its executable, and the engine and client now follow the answers:

• Diplomacy: contact between empires is lost when no warp path joins their colonies any more.
• Combat:
  • how computer-controlled pieces choose targets and squares;
  • formations, launches, boarding and ramming;
  • mine strikes, battle checks, and the combat simulator's sides.
• Ships and fleets:
  • every object shares one slot order;
  • orders given to a fleet are copied to its members;
  • turn-based attacks and cloaking follow the original;
  • ships are named " NNNN".
• Computer players:
  • how they answer messages and demands;
  • transports, repairs and warp-point work;
  • mine and satellite layers;
  • rebel empires.
• Interface:
  • Windows: Options (per computer and per empire), Log, Planets, Construction Queues and all the combat windows;
  • Main window: the system grid, which order buttons are available, colours, status icons and ship headings;
  • Keys: every hotkey, all of them rebindable;
  • Yes/No prompts: Enter and Esc mean No;
  • Sound: sound effects and music;
  • Title screen: the original's buttons and a Credits screen.

Saved games from earlier versions can't be loaded (save format 3).

Downloads

File	For
OpenSE4-0.3.0-windows-x86_64-setup.exe	64-bit Windows 10 and 11: the installer
OpenSE4-0.3.0-windows-x86_64.zip	64-bit Windows 10 and 11: the same programs to run from any folder
OpenSE4-0.3.0-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)
OpenSE4-0.3.0-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, 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. You can also 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.
• The Windows build and installer have been tested under Wine, not yet on real Windows.
• The lessons have been checked step by step and by computer-played runs, but not yet played through by hand. The fortress and conquest training goals depend on how you play and are untested.
• 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.