Sword of the Stars (2006) reverse-engineering worklog. Infra docs live in trikilli services/re-lab.md.
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alex 1893751ffa PAR: roll parity -- an AI client's per-turn RNG word count is not fixed at any scope
The hypothesis under test was the lockstep discipline: that each run of an AI client consumes a
fixed number of draws regardless of the path it takes, so a reimplementation could keep the
generator aligned with the right COUNT and order of draws while getting the decisions wrong.

It is false, and it fails at four scopes. Measured with a new bracket on
StrategyClient::OnResumePlaying over the per-client generator at +0x134, six runs across VM140 and
VM145, five fresh processes; every unpinned run's autosaves are byte-identical to the published
oracle, so the instrument is behaviour-neutral (rules 19 and 26 both discharged).

  across clients   turn2->turn3: 3 / 0 / 0 words for AI players 32 / 496 / 512; human 0
  across turns     client 32: 3 words on turn 2, 7 on turn 1
  across processes client 512 makes ONE cl_RandRange call on turn 1 -- the research-target
                   tie-break at 0x006a8495, phase 18 -- and it cost 1 word in one process and
                   3 in another, because RNG_NextInt is an unbounded rejection loop
  per site         RNG_Chance costs ZERO words at p<=0 and p>=1

Twenty-one live draw sites in an AI turn, in twelve functions (plus two provably dead ones); two
fired on the reference turn, three on turn 1. Only three are unconditional, and all three only
given that their enclosing function was called. Six of client 32's seven turn-1 words come from
the ship-design composer 0x006ad700, which is also where the only loop-carried draw lives.

Also: cl_RandFloat 0x00579c70, a third cl_* RNG facade, found twice independently. It reaches
RNG_NextFloat by a TAIL JUMP, so no rel32 sweep for the entry points can see it -- which is why
ai-turn-logic.md 5's 'zero NextFloat calls from the AI module' reads as true and is not. All 29
call sites of the three facades are inside the AI band: the cl_* RNG facade is AI-only surface.

Positives for the engine: the AI draws from nothing but its own client's generator (foreign_words
0 on every bracket), the human client draws nothing at all, and the per-turn cost is single digits.
Rung B is unaffected. Rung C needs the decisions.
2026-09-08 19:33:00 -04:00
campaign board: lane CB - C-exact proven, pinned seeds collapse three runs to one autosave; k=6 not closed 2026-09-08 19:28:04 -04:00
findings PAR: roll parity -- an AI client's per-turn RNG word count is not fixed at any scope 2026-09-08 19:33:00 -04:00
ghidra PAR: roll parity -- an AI client's per-turn RNG word count is not fixed at any scope 2026-09-08 19:33:00 -04:00
guides resolution: byte-match survives as C-exact/C-set; tie set is a draw support not equal cost; rule 26 on self-consistent controls 2026-09-08 18:38:37 -04:00
notes init commit 2026-09-07 12:31:56 -04:00
objects regenerate both headers (669 addresses); track objects/generated so the shared clone stops sitting dirty 2026-09-08 07:36:16 -04:00
scripts lane V2: vtable inversion — resolve indirect call edges image-wide 2026-09-08 12:05:05 -04:00
tools CB: the turn-command stream, captured and bound to the autosave it produced 2026-09-08 19:18:57 -04:00
verify PAR: roll parity -- an AI client's per-turn RNG word count is not fixed at any scope 2026-09-08 19:33:00 -04:00
.gitignore lane D: automated struct recovery from the IStreamable serializers 2026-09-08 05:51:37 -04:00
README.md guides: RE how-to for 2000s MSVC/DX9 games (98 sources); queue replay-checksum, class recovery, apitrace/TTD 2026-09-07 18:05:58 -04:00

sots-re

Reverse-engineering worklog for Sword of the Stars (2006, SOTS1) — the 32-bit DX9 original + expansions. The nitty-gritty: static/dynamic analysis notes, Ghidra & ReVa scripts, function/struct maps, D3D9 call traces, decomp progress, findings.

Where this runs

Analysis lab on spicy (PVE, 192.168.3.201):

  • CT111 sots-re — Linux workspace: Ghidra + headless ReVa server, radare2/rizin/cutter, binwalk. Hosts the Samba share and this repo's working tree at /srv/re-lab/notes.
  • VM140 sots-re-win10 — Win10 runtime + dynamic analysis (x64dbg, Cheat Engine, RenderDoc/apitrace, DXVK→CPU-Vulkan for GPU-less rendering).

Infra (guests, storage, network, share, ReVa endpoint) is documented from the system-maintainer POV in trikilli → services/re-lab.md. This repo is everything else.

Layout

  • findings/ — the running findings log (append-only), one file per subsystem.
  • ghidra/ — exported scripts, data-type archives, struct definitions.
  • traces/ — D3D9 / Win32 API call captures + analysis.
  • scripts/ — helper tooling (loaders, extractors, parsers).
  • notes/ — session notes, scratch, hypotheses.

Ownership / legality

Game binaries come from the owner's own GOG/Steam copy. RE is for personal interoperability, bug-fixing, and preservation. Binaries themselves are not committed here (see .gitignore) — they live on the lab's Samba share /srv/re-lab/samples.

Campaign (how this repo is run)

A 4-agent crew (defined in ~/.claude/agents/re-*.md) runs the exploration: re-quartermaster (backlog + board) → re-analyst (maps via ReVa) → re-verifier (proves vs real data; old-vs-new differential once reimpl starts) → re-scribe (files the note, links it, commits).

  • campaign/board.md — live status board (start here).
  • Live tracking = Forgejo issues on alex/sots-re (labels status/* are the kanban columns; type/*, conf/*). campaign/board.md is the editable mirror — publish with scripts/forgejo_campaign.py bootstrap (needs FORGEJO_TOKEN).
  • campaign/backlog.md — prioritized target queue.
  • campaign/open-questions.md — unresolved threads.
  • findings/_template.md — the record format every finding follows.
  • findings/{objects,control-flow,subsystems}/ — the growing engine map.
  • verify/{parsers,traces,harness,results}/ — validation: struct parsers now, golden-trace replay + shim compare-mode for reimplementation.
  • ghidra/ — exported scripts + datatype archives.

Approach & north star: findings/00-strategy.md. Binary facts: findings/01-fingerprint.md.

Sibling repo

alex/sots-engine — the from-scratch engine source (clean-room, public-capable). This repo keeps the evidence + planning for both; binary facts cross over only via ghidra/addresses.json → tools/gen_addresses.py.

  • guides/re-windows-2000s-howto.md — annotated bibliography + how-to for RE of mid-2000s MSVC/DX9 Windows games, with our-experience call-outs.