Outpost

Unofficial open-source implementation of the board game Outpost (James Hlavaty, 1991) for boardgamers.space (BGS). Not affiliated with TimJim or Stronghold Games.

Two packages:

• packages/engine (outpost-engine) — pure TypeScript rules engine plus the BGS wrapper contract (wrapper.ts). Dependency-light (only seedrandom), deterministic via a seeded PRNG, state stays JSON-serializable at all times.
• packages/viewer (outpost-viewer) — Svelte 5 browser UI, built as a self-contained IIFE bundle for the BGS iframe (window.outpost.launch(selector)).

Rules set

The engine implements the 20th Anniversary / Expert Rules v1.32 set, which is the version Stronghold Games adopted as the base rules:

• Hand capacity 10 (research & microbiotics cards don't count against it)
• Research factories cost 30 and require a Laboratory; buying a New Chemicals factory requires spending a research card
• Over-capacity players discard before actions (after production)
• Robots don't count against the population limit; robot ownership is capped at (Robots upgrades × population)
• Victory: 75 VP (manned factories + upgrades); ties on VP in purchase order are broken by total credits spent
• Market refill via d4 / d10 / d12+1 by game era (leader VP, per the v1.32 setup chart), including the "very rare" fallback (a second consecutive round beginning with every upgrade 1-4 / 1-10 already purchased advances the era) and the next-lower-numbered-card cascade when a rolled type is exhausted. The Kicker era follows the same game era.

Data notes / deviations

Production card distributions and averages follow the official reference sheet v1.32 and owner-verified card counts (BGG thread 2801038). Water, titanium, new chemicals and orbital medicine decks are confirmed card-by-card; the remaining decks (ore, research, microbiotics, ring ore, moon ore) use symmetric bell distributions matching the confirmed deck sizes and official average values, since exact value splits were not available. The original edition's physical decks differ in a few counts (e.g. only two "4" water cards).

• In-game randomness (deck shuffles, die rolls, tie-breaks) is fully deterministic from the game seed; BGS supplies the seed, so replays and save/load are exact.
• Random VP tie-breaks in purchase order are resolved by seat order (never relevant online).
• Auction winners receive no change when overpaying, per the rules.
• Mega production cards (expert rule 12.1) are implemented: with 4+ operated water/titanium/ new-chemicals factories you may elect 1 Mega card per group of 4 (fixed printed value — Mega Water 30, Mega Titanium 44, Mega New Chemicals 88 — that counts as 4 cards toward hand capacity). The election is blind, made before any of that round's production draws are revealed, and decided per group of 4; only operated factories count (never upgrade freebies or Kicker bonuses). Mega cards are a separate face-up pool of 9 per type; a spent or discarded mega returns to its pool. The pool size is the physical component count — no rulebook text covers exhaustion, so an empty pool simply means you take the normal draws instead (this is an inference, not a documented ruling).
• Tom Lehmann's 1994 Expert Game v1.32 document lists Laboratory at 80 and Ecoplants at 30; this implementation follows the 20th Anniversary printing at 100 and 50. If a physical copy shows the lower values, it's a one-line change in packages/engine/src/data.ts.

Kicker expansion (game option)

The kicker game option enables the Kicker expansion: a separate set of Kicker slots (1/2/3 by player count for 2-4/5-7/8-9) filled from era piles (I → II → III). Kicker cards are auctioned like colony upgrades. All nine types are implemented.

• Confirmed card data (2011 rulebook + BGG): Ice Prospector 10/1, Robot Prototype 10/0, Smelter 15/1, Wily Trader 10/1, Launch Facility 75/2, Merchant House 60/1, New Chemicals Factory Prototype 60/0, Biosphere 250/25. Refinery's printed cost/VP are not documented — the rulebook has a production error (its card image is missing). As the Era II analog of Ice Prospector (mirroring Wily Trader 10/1 → Merchant House 60/1) it is provisionally 60/1, a one-line change in packages/engine/src/data.ts (KICKER_SPECS).
• Ice Prospector / Refinery draw the extra card and discard the cheapest of the just-drawn cards of that type automatically (the obvious choice; no interactive pick).
• The Era III pile holds only Biosphere (the single Era III type), per the rules.
• Wily Trader / Merchant House run an exchange step at the end of the discard phase (after all excess cards are discarded), in player order. Each owner may hand one Ore/Water/Titanium (Wily Trader) or Research/Microbiotics/New Chemicals (Merchant House) card to another player holding a non-Mega card of the same type; that player must hand back a higher-valued card of the type if they have one, else they return the given card. The target's return is resolved automatically (their lowest higher-valued card — the obvious choice — so the target makes no decision). A card taken this way is parked face-down on the Kicker card until the phase ends, so it cannot be taken again by another exchange that phase. Mega cards cannot be offered or taken. Each owner exchanges at most once per round (per the "one card" wording).

Development

pnpm install
pnpm dev      # viewer dev server + mock backend harness (human + bots)
pnpm check    # fmt:check + lint + tsc + test + build

Dev harness URL params: ?players=4&seed=xyz&delay=700&auto=1&fastBid=1&kicker=1.

Node >= 24, pnpm 11 (see packageManager). All dependencies pinned.

Deploying to BGS

• Engine: npm pack the built outpost-engine (or publish) and register it as the game engine in the BGS admin panel; entry point dist/wrapper.js.
• Viewer: upload packages/viewer/dist/outpost-viewer.iife.js + outpost-viewer.css (and the .map with a shared bundle id if you want devtools sourcemaps).

See https://docs.boardgamers.space/guide/adding-a-game.

License

AGPL-3.0.