add lighthouse rules description

packages/shared/src/templates/lighthouse_rules.ts

@@ -0,0 +1,37 @@
+export const lighthouseRules = `
+Introduction
+------------
+Lighthouse is a variant of Go / Baduk where players have partial information about the board position. Stones cast light rays that illuminate fields for their owner.
+
+Partial Information
+-------------------
+Players see different parts of the true (hidden) board state. The visibility of fields and stones is different for each player.
+
+Visibility
+----------
+Every stone illuminates fields for its owner in straight lines extending in all directions until meeting another stone.
+- Illuminated fields display their true state (empty or black or white stone).
+- Not illuminated fields display their last known information.
+
+Last Known Information
+----------------------
+The last known information of a field is the state from the last time when the field was illuminated, or "empty" if the field was never illuminated before.
+
+Revealing a field
+-----------------
+When a stone is placed on a field that is not illuminated, it is possible that this field is secretly occupied. In this case, the players move does not result in a stone placement, but the field gets revealed.
+
+Revealing a field results in updating the last known information for this player.
+
+Similarly when a chain gets captured, the owner can deduce that adjacent fields are occupied by the other color. To aid the player, the adjacent fields are revealed.
+
+Ko and self capture
+-------------------
+A move is not allowed if it results in repeating a previous board position, and both times occurred during the same players turn.
+
+Self capture is allowed.
+
+Observer view
+-------------
+Observers can see a much smaller portion of the board. This is to avoid that players can gain information by looking at the observer view.
+`;

packages/shared/src/variants/lighthouse/lighthouse.ts

@@ -3,6 +3,7 @@ import { Coordinate, CoordinateLike } from "../../lib/coordinate";
 import { Grid } from "../../lib/grid";
 import { examineGroup, getGroup, getOuterBorder } from "../../lib/group_utils";
 import { SuperKoDetector } from "../../lib/ko_detector";
+import { lighthouseRules } from "../../templates/lighthouse_rules";
 import { Variant } from "../../variant";
 import { Baduk, Color } from "../baduk";
 import { NewGridBadukConfig } from "../baduk_utils";
@@ -249,4 +250,5 @@ export const lighthouseVariant: Variant<NewGridBadukConfig, LighthouseState> = {
   description:
     "Each stone casts rays of light that illuminate fields in a line.",
   time_handling: "sequential",
+  rulesDescription: lighthouseRules,
 };