Impressions Games Archive

A reference site for the Impressions Games / Sierra City Building series — Caesar (1992), Caesar II, Caesar III, Pharaoh, Zeus and Emperor — and for the open-source engines and modding work around them.

→ https://0x695.github.io/IGA/

Players and nostalgics are welcome, but the reader this is built for is a modder or developer who arrived from a search with one specific question and wants the answer in one or two clicks.

What makes it different

Fan sites for this series are good at strategy and thin on technical detail. This one inverts that. Every table here was read out of an open-source engine by a script that asserts its own output, and every page names the file its figures came from.

The rule that follows matters more than any single table: where something could not be checked, the page says so instead of rounding the gap up into confidence.

• Caesar III has no cost or labour column, because those numbers live in c3_model.txt — a file that ships with the game and that any mod may rewrite. Publishing one installation's values would be right for one copy of the game and quietly wrong for every other.
• Emperor has no production table, because the only figures available are a walkthrough author's own estimates.
• fire_proof is parsed from the engine and deliberately not emitted: the column header and the struct field make opposite claims about the same byte, and no consuming code was found.
• Pharaoh's peaceful/military branch labels are absent — the choice pairs are real and visible in the engine, but which half is the military one is not recorded anywhere checkable.

Open-source projects carry a status — active, dormant or dead — with the date and short SHA of their last commit beside it, so the claim has evidence attached and a reader can see how stale the answer is.

What is on it

Six self-contained game hubs. Each always shows the same twelve sections, empty or not: credits, file formats, buildings, housing, mechanics, production, campaign, cheats, open-source engines, how to play it today, tools and mods, manual and community. An empty section says so rather than disappearing.

The hubs track eleven open-source engine projects (eight active, two dormant, one dead), each with its author, status, and last commit pulled from GitHub, and a link to a browser build where one exists (Augustus, Akhenaten, the Caesar II port and Gaius). They also list fan tools and mods, such as the widescreen patchers for Zeus and Emperor, and where to buy each game today.

Hung off those hubs:

File formats	Sixteen written specs — SG/.555, .eng, Caesar III's .map, .sav and c3_model.txt, Caesar's eight asset and save formats, Caesar II's .SAV and text, Zeus's .sav container
Buildings	Filterable references for Caesar, Caesar II, Caesar III, Pharaoh and Zeus
Campaigns	Every game, from mission configs where an engine has them
Housing	Ladders for every game; Caesar II's has land-value thresholds and per-house capacity
Production	Chains for Caesar, Caesar II, Caesar III, Pharaoh and Zeus, with a rate only where the source states one
Mechanics	The walker model, Caesar's city growth and taxes, Caesar II's growth tiers and what holds a house back, Zeus's city limits, and how the original Emperor runs

Plus a devlog covering how it was built — including the mistakes — and Pagefind search across the lot.

Running it

npm install
npm run dev      # http://localhost:4321/IGA/
npm run build    # astro build + pagefind, into dist/
npm run preview

Note the /IGA/. The site deploys as a GitHub Pages project site, so it lives under a base path and the config defaults to the deployed values rather than pretending the base is /. Serving dist/ by hand needs it under a matching directory, not at a server root.

Search is Pagefind and its index is built from the finished site, so under npm run dev it does not exist — /search says so rather than looking broken. Use npm run build to exercise it.

Regenerating data

npm run buildings    # Caesar III from Julius, Pharaoh from Akhenaten, plus Zeus, Caesar and Caesar II
npm run housing      # housing ladders, all six games
npm run production   # production chains, five games
npm run engines      # last commit date of every engine project and tool
npm run links        # check every outbound link

src/data/buildings.json, housing.json and production.json are output. Edit the script and re-run it; hand edits are overwritten and, worse, are not checked. Each script asserts its own work before writing — the buildings one joins an enum to a properties table by numeric index, which is exactly the operation that fails silently, so it verifies the row count and fourteen independently known footprints first.

npm run images and npm run social need the original screenshots and box art, which are not in this repository. The committed WebP derivatives under public/images are what the site serves, so a clone builds without them.

Layout

src/data/               the content, as typed JSON
src/content.config.ts   the Zod schemas it is validated against
src/pages/              Home, the six hubs and their sub-pages, formats,
                        mechanics, devlog, search
src/components/         nav, footer, cards, spec blocks
public/images/          screenshots and box art, as WebP
scripts/                the generators and the link checker

Content is data, not markup: adding an engine project or a file format means adding an entry under src/data/, and every hub whose game it names picks it up. Formats are stored once with a list of the games that use them — .sg3 is one format used by three titles, not three entries.

Deploying

Pushes to main publish via .github/workflows/deploy.yml. Nothing hardcodes a domain: the workflow reads the real origin and base path from actions/configure-pages and passes them to the build, so the same code serves a project site at user.github.io/repo/ and a custom domain later without an edit. The workflow enables Pages itself on first run.

One guard worth knowing about: the build fails if dist/pagefind is missing. astro build alone produces a perfectly working site whose search box finds nothing, and that failure is otherwise silent.

Credits and scope

This archive holds knowledge and links, not game files. Screenshots and box art illustrate the games they document and are credited inline. Open-source projects are described, linked and briefly quoted with attribution; community guides are linked and read, never republished — facts can be sourced, prose cannot be copied.

Built on Julius, Augustus, Akhenaten, eZeus, the Caesar II reconstruction and Gaius, whose authors did the actual reverse engineering. This site mostly reads what they wrote down.

Impressions Games Archive is a fan-run reference. Not affiliated with Impressions Games, Activision, Sierra, or Tilted Mill.