Where this came from

00 · What this is

A retheme, not a redesign

Xenocide is a cooperative card game about an uprising against a cosmic hierarchy. Under the fiction, the rules are Regicide's, unchanged: a published game whose mechanics are, in our view, close to perfect and not in need of our improvements.

What is original here is everything around them: the world, the vocabulary, the twelve entities, the artwork, the interface, and eight complete visual identities the whole thing can wear. The split is deliberate and total. Nothing mechanical was invented; nothing presented was borrowed.

01 · The debt

Regicide, by Badgers From Mars

Regicide was designed by Paul Abrahams, Luke Badger and Andy Richdale, with art by Sketchgoblin, and published by Badgers From Mars. It is a genuinely brilliant piece of design: an entire cooperative game with real strategic depth, played with a standard 52-card deck and two jokers, and the rules fit on a single folded sheet.

Everything mechanical here is theirs. The four steps, the suit powers firing at the combined value, Hearts before Diamonds, the exact-kill recruitment, the banked spades that come alive when a Heretic lands. All published rules, implemented faithfully and tested against the rulebook rather than against memory.

This is a personal, non-commercial build. If you like it, buy the physical game. It is better in your hands than on a screen, and it fits in a pocket.

01b · Why the Mythos

The reskin the rules were asking for

The central rule is immunity: each entity denies the Force of its own suit. It is a lovely mechanic and, dressed as a fallen dynasty, it means very little. Why would a diamond-hearted noble resist card-drawing in particular?

Dressed as a cosmic hierarchy, the same rule reads as doctrine. Each of these things has a domain, and inside its domain nothing you bring works. Dream buys nothing from a thing that already knows everything; Void opens no absence in front of absence itself. Nothing in the rules changed. Only the reason changed, and the reason is what makes the rule feel inevitable rather than arbitrary.

The Heretic is where the two halves meet: a card that deals nothing, that the Pantheon does not take seriously, and that is therefore the only thing able to make an Ancient notice anything at all.

02 · What was made

Original from the frame in

No asset from the retail game is used, and no image file of any kind is used for the deck. Every card is CSS. Every one of the twelve Pantheon is inline SVG, drawn for this project, painting in exactly two colours so that it re-inks itself when the deck changes stock.

The entities themselves are public domain: Lovecraft, Chambers, Clark Ashton Smith. What is original is the drawing, the naming, the interface, and the eight complete visual identities the whole thing can wear.

Four of the twelve, in whichever skin you have selected. Switch skins above and watch them re-ink, and that is one token changing, not twelve drawings.

03 · The engine

Rules first, everything else after

The rules engine is pure Python with no knowledge of the web, seeded so any game can be replayed exactly, and covered by fifty tests that stack the deck to reach the situations a shuffled deal almost never produces: the retroactive spades, the exact kill, the two ways to lose.

That order mattered. Hidden information is enforced on the server, so no browser is ever sent another player's hand. The move advisor works by playing candidate moves on a copy of the real engine rather than modelling the rules a second time. And because the whole thing is deterministic and rewindable, the coach can tell you exactly what would have happened had you played differently, not a simulation of it but the actual line.