An experiment in implementing the Legendary ruleset. Very incomplete. Includes:
- A Haskell API server component in
api. This is the most interesting part. - A react frontend in
frontend. This is pretty jank and currently mostly for ease of testing the API.
Requires standard Haskell stack and npm development environments.
cd api
stack ghci # choose legendary-bench:exe:legendary-bench-exe
main
npm start
The state of the game is represented by the board. The only way the board can be modified is by applying an action. An action is able to halt application if it is unable to complete due to insufficient player choices (i.e. the player hasn't selected a card yet). When an action halts, it provides a resume action to be stored in the board. When the set of player choices changes, the action can be resumed by applying the saved action.
Perhaps surprisingly, there is no way to apply an action directly via the API! The entire game is modeled as a sequence of actions that halt when player action is needed. Applying the intial prepare game action will halt on the first need for player choice, and all subsequence resumes will also halt until the game terminates (win/loss/draw).
Actions are monoidal, meaning that two actions can always be combined into
a single one using the ActionCombine action. When applying a combined action,
if the left side halts then its resume action is wrapped such that the right
hand side will be applied after it is successfully resumed. In this way, long
action chains can easily be constructed and will behave as expected.
The core engine code knows nothing about any specific cards in the game. They
are implemented using a custom LISP-like language in the cards directory
(customizable with CARDS_LANG env var). For kicks, this language also
features static type inference and checking.
(make-hero "Unstoppable Hulk" "Instinct" 4 5
"You may KO a Wound from your hand or discard pile. If you do, you get +2 Attack."
(.
(add-attack-plus 2)
(add-play-effect
@(choose-card
"Choose a wound from hand or discard to KO"
(filter
is-wound
(concat-map cards-at-current-player-location ["Hand" "Discard"])
)
(fn [card] (combine (ko card) (attack 2)))
noop)
)))
(make-hero "Hey, Can I Get a Do-Over?" "Instinct" 3 3
"If this is the first Hero you played this turn, you may discard the rest of your hand and draw four cards."
(.
(add-attack 2)
(add-play-effect
@(if
(== [current-card] (cards-at-current-player-location "Played"))
(choose-yesno "Discard your hand?"
(combine
(discard-hand current-player)
(draw 4))
noop
)
noop
)
)))
There's no really great reason for this I just thought it would be fun. Which it was.