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.