--- title: "Lane crossing to home bays: API" package: "@phaser-ae/frogger" tier: Pro version: 3.0.0-5 released: 2026-10-14 updated: 2026-10-20 description: "Complete rules for a lane-crossing game on a board you describe: rows of traffic and river, platforms that carry and dive, and home bays to fill, every board certified crossable." url: https://phaser.io/packs/frogger/api site: Phaser - https://phaser.io --- # Lane crossing to home bays: API `@phaser-ae/frogger` — Lane-crossing rules where you set the rows, lane order, directions, speeds, platforms, divers, bays and rules, every board certified completable, as in Frogger. ## The pack ### `frogger` ```ts function frogger():Pack<{frogger:typeof rules}> ``` Lane-crossing rules over lane-control for any board: rows, lanes, platforms, bays and rule options are configurable; the classic arcade board is the default preset. ## Functions ### `createFrogger` ```ts function createFrogger(definition: FroggerDefinition): FroggerGame ``` A replayable crossing over a validated definition: hops, time, next-level, undo/redo and validated saves. ### `froggerBonuses` ```ts function froggerBonuses(s: Pick): { fly: number | null; flyKind: string | null; croc: number | null; lady: FroggerObject | null; } ``` The bay holding the bonus insect (and which kind), the bay holding a threat, and the escort piece while she can be picked up. ### `froggerDefinition` ```ts function froggerDefinition(input: FroggerOptions, attempt = 0): FroggerDefinition ``` Lay out and validate one candidate course (attempt 0–7 varies the seeded formation). Throws naming the bad option, row or lane. ### `froggerHint` ```ts function froggerHint(g: Pick): { action: FroggerAction | null; reason: string; } ``` One safe action from the current state, or why none was found. Never changes the game. ### `froggerObjects` ```ts function froggerObjects(s: Pick): FroggerObject[] ``` Derived objects and timed bonuses use the exact same lane samples as collision and carrying. ### `generateFrogger` ```ts function generateFrogger(o: FroggerOptions): { definition: FroggerDefinition; certificate: FroggerAction[]; complexity: { traffic: string[]; river: string[]; divers: string[]; hazards: string[]; homeOrder: number[]; }; timing: { tickMs: number; hopMs: number; turtleSurfaceMs: number; turtleWarningMs: number; turtleSubmergedMs: number; turtleRisingMs: number; provenance: string; }; } ``` Generate a course and its completion certificate: up to eight seeded formations are tried, and the winner is replayed independently through every bay without losing a frog. Throws naming the row that blocked every route. ### `layoutFrogger` ```ts function layoutFrogger(o:{seed:number;difficulty:'easy'|'medium'|'hard';level:number;turtleSurface:number;turtleUnderwater:number;board:FroggerBoard;rules:FroggerRules},attempt:number):FroggerLayout ``` Lay a validated board out as concrete lanes. Every seeded choice is drawn in a fixed order: per row lane its count, then each piece's kind and length, its spacing weights, offset and first diver; then level swaps, overlay lanes and the escort piece. ### `planFroggerHome` ```ts function planFroggerHome(game: Pick, budget = 50000): FroggerAction[] ``` Bounded predictive search from the actual state; candidate hops simulate every collision tick. Throws a `FroggerSearchError` when no route is found. ### `resolveFroggerRules` ```ts function resolveFroggerRules(input:FroggerRulesInput={},base:FroggerRulesInput={}):FroggerRules ``` Merge rule overrides over the classic defaults and check every range. Throws naming the bad rule. ### `solveFrogger` ```ts function solveFrogger(d: FroggerDefinition): FroggerAction[] ``` Fill every bay, then independently replay the exact timed commands. ### `validateFrogger` ```ts function validateFrogger(d: FroggerDefinition): void ``` Check a complete definition, including any edited by hand. Throws on the first problem. ### `validateFroggerBoard` ```ts function validateFroggerBoard(board:FroggerBoard):void ``` Check a board design. Throws a message naming the row, lane or field at fault. ### `validateFroggerRules` ```ts function validateFroggerRules(r:FroggerRules):void ``` Check a complete rules object. Throws naming the bad rule. ## Constants ### `froggerDefaultRules` ```ts const froggerDefaultRules: FroggerRules ``` Classic arcade rules. ### `froggerKind` ```ts const froggerKind = (kinds:Record,kind:string):FroggerKind|undefined=> … ``` Look up a kind's behaviour without inheriting object prototype names. ### `froggerPresets` ```ts const froggerPresets: Record<'classic'|'curb-hopper',FroggerPreset> ``` Ready-made designs: `classic` (the default board and rules) and `curb-hopper`. Pass one as `preset`, or copy and edit its board. ## Types ### `Direction` ```ts type Direction = 'up' | 'down' | 'left' | 'right' ``` A one-cell hop. ### `Frog` ```ts type Frog = { … } ``` The frog: centre `x` in cells, `row` (fractional mid-hop), `ride` the speed it is being carried at, `queued` a buffered hop. - `x: number` - `row: number` - `facing: Direction` - `hop: FrogHop | null` - `escort: boolean` - `ride: number` - `queued: Direction | null` ### `FroggerAction` ```ts type FroggerAction = Advance | { kind: 'hop'; direction: Direction; } | { kind: 'next-level'; } ``` Commands: advance time, hop, or move on after a completed level. ### `FroggerBoard` ```ts type FroggerBoard = { … } ``` The playfield: any number of rows from start to home, each lane's direction, speed, pieces, gaps and divers, the bays, and timed bonuses. Plain JSON. - `name?:string` — Presenter name for the board (`classic`, `curb-hopper`). - `width:number` — Field width in cells, 4–64. Positions are piece left edges and frog centres in cells; hops are one cell. - `start?:number` — Frog start centre in cells; default the middle (`width / 2`). - `rows:FroggerRow[]` — 3–30 rows, bottom to top: row 0 must be `safe` (the start) and the top row must be `home`. - `kinds?:Record` — Behaviour of particular piece kinds (turtle parts, crocodile jaws, rideable otters). - `hazards?:FroggerOverlay[]` — Overlay hazard lanes, gated by level. - `fly?:{kinds?:string[];period:number;active:number}|null` — A bonus insect that sits in a random empty bay for `active` of every `period` seconds; kinds take turns. Absent: none. - `homeCroc?:{kind?:string;from?:number;period:number;active:number}|null` — A threat that occupies a random empty bay for the last `active` of every `period` seconds, from level `from` (default 1). Needs `rules.hazards`. - `lady?:{lane:string;kind?:string;period:number;active:number}|null` — An escort (the lady frog) riding one piece of a river lane for `active` of every `period` seconds; land on her and bring her home. - `messages?:Partial>` — Death message overrides by cause. ### `FroggerCause` ```ts type FroggerCause='vehicle'|'water'|'dive'|'drift'|'miss'|'occupied'|'threat'|'bite'|'hazard'|'timeout' ``` Why a frog was lost: a vehicle; open water; a support that dived; carried or hopped off the side; the bank between bays; an occupied bay; a bay threat; a mouth; a hazard; the timer. ### `FroggerDefinition` ```ts type FroggerDefinition = { … } ``` A concrete, validated course: the board laid out as lane-control lanes, with every timing in milliseconds. - `attempt: number` — Layout attempt 0–7 that certified. - `options: FroggerSettings` — Settings that regenerate this course. - `rows: { kind: FroggerRow['kind']; name: string; edges: FroggerEdges; }[]` — Row kinds, names and edge policy, bottom (start) to top (home). - `field: LaneField` — Wrapping lanes. - `road: { row: number; lane: string; }[]` — Vehicle lanes by row. - `river: { row: number; lane: string; }[]` — Platform lanes by row. - `hazards: { row: number; lane: string; }[]` — Overlay hazard lanes by row. - `kinds: Record` — Piece kind behaviour. - `homes: number[]` — Bay centres in cells. - `between: string` — Presenter name for the bank between bays. - `start: number` — Frog start centre in cells. - `hopMs: number` — Hop milliseconds. - `radius: number` — Frog half-width in cells. - `fly: { kinds: string[]; period: number; active: number; } | null` — Bay bonus insect, milliseconds; null for none. - `homeCroc: { kind: string; period: number; active: number; } | null` — Bay threat, milliseconds; null when off or below its level. - `lady: { lane: string; item: string; kind: string; period: number; active: number; } | null` — Escort piece, milliseconds; null for none. - `messages: Record` — Death messages by cause; empty derives the text from the piece kind. ### `FroggerDive` ```ts type FroggerDive = { … } ``` A diving cycle in seconds. Missing values come from the `turtleSurface`/`turtleUnderwater` options and the .75 s warning and .35 s rising defaults. - `surface?:number` — Seconds surfaced and safe; default the `turtleSurface` option (5). - `warning?:number` — Seconds of visible warning, still safe; default .75. - `submerged?:number` — Seconds under water, giving no support (for a `jaws` kind: mouth open); default the `turtleUnderwater` option (1.1). - `rising?:number` — Seconds coming back up, still giving no support; default .35. - `offset?:number` — Seconds into the cycle at time zero; several divers in one lane are spread evenly from here. Default 0. - `pace?:number` — Runs the whole cycle faster (above 1) or slower (below 1); .25–4, default 1. ### `FroggerEdges` ```ts type FroggerEdges='block'|'open' ``` Whether a sideways hop past the field edge is refused (`block`) or allowed, so the frog lands or drifts off (`open`). ### `FroggerGame` ```ts type FroggerGame = Timeline & { hint(): { action: FroggerAction | null; reason: string; }; } ``` A replayable crossing with a safe-move hint. ### `FroggerHomeRow` ```ts type FroggerHomeRow = { … } ``` The top row: bays to fill, with bank (bushes, shrubs) between them. - `kind:'home'` — Row kind. - `name?:string` — Presenter name. - `bays:number[]` — Bay centres in cells from the left edge, 1–16 of them; each must be filled once. - `between?:string` — Presenter name for the bank between bays; default `bush`. Landing on it loses a frog. ### `FroggerKind` ```ts type FroggerKind = { … } ``` Behaviour of a piece kind beyond its lane's role. Kinds not listed behave plainly: vehicles kill, platforms carry, hazards kill. - `parts?:number` — Identical parts drawn across one piece, e.g. 3 for a turtle trio that moves and dives as one; 1–8, presentation only. Default 1. - `cycle?:'dive'|'jaws'` — What the activity cycle means: `dive` (default) — submerged and rising pieces neither carry nor harm; `jaws` — the piece stays and its mouth is lethal only while submerged (open). - `mouth?:{length:number;end:'front'|'back'|'left'|'right'}` — A lethal end, in cells: crocodile jaws, an otter's head. `front` and `back` follow the lane's direction. - `ride?:boolean` — A hazard-lane piece the frog may ride: only its mouth is lethal, and on a river row its back carries the frog. - `message?:string` — Death message for this kind's bite or contact; default derived from the name (`A snake caught you`, `Crocodile jaws`). ### `FroggerLane` ```ts type FroggerLane = { … } ``` One lane of moving pieces: a road row's traffic, a river row's platforms or a hazard overlay. - `id?:string` — Unique lane id, a lowercase identifier of at most 24 characters. Default `road-`, `river-` or `hazard-`. - `direction:'left'|'right'` — Which way the pieces travel. - `speed:number` — Cells per second at medium difficulty on level one, before difficulty and progression multipliers; 0–30. 0 holds still. - `pieces:FroggerPiece[]` — Piece templates (1–16), used in turn along the lane. - `count?:FroggerTuned` — How many pieces (0–64); a `[min, max]` range picks by seed. Default one per template. - `gap?:FroggerTuned` — Minimum clear cells between pieces, or between convoys; spare room is shared out by seed. Default 1. - `group?:number` — Pieces per convoy, travelling `spacing` apart; default 1 (no convoys). - `spacing?:number` — Clear cells between pieces inside a convoy; default the gap. - `divers?:number|'all'` — How many pieces dive, chosen by seed, or `'all'`. Default 0. - `dive?:FroggerDive` — The divers' cycle. - `swap?:{from:number;kind:string;dive?:FroggerDive}` — From level `from`, one piece (chosen by seed) becomes `kind` with this cycle: the classic crocodile log. Needs `rules.hazards`. ### `FroggerLaneRow` ```ts type FroggerLaneRow = { … } ``` A road row (its lane's pieces are lethal vehicles) or a river row (its lane's pieces are the only footing, and carry the frog). - `kind:'road'|'river'` — Row kind. - `name?:string` — Presenter name. - `edges?:FroggerEdges` — Side edges; default `block`. - `lane:FroggerLane` — The row's traffic or platforms. ### `FroggerLayout` ```ts type FroggerLayout = { … } ``` A board resolved into lane-control lanes and row roles; part of a definition. - `rows:{kind:FroggerRow['kind'];name:string;edges:FroggerEdges}[]` — Row kinds, names and edge policy, bottom to top. - `field:LaneField` — Concrete wrapping lanes. - `road:{row:number;lane:string}[]` — Vehicle lanes by row. - `river:{row:number;lane:string}[]` — Platform lanes by row. - `hazards:{row:number;lane:string}[]` — Overlay hazard lanes by row. - `kinds:Record` — Piece kind behaviour. - `homes:number[]` — Bay centres in cells. - `between:string` — Presenter name for the bank between bays. - `start:number` — Frog start centre in cells. - `fly:{kinds:string[];period:number;active:number}|null` — Bay bonus insect, in milliseconds. - `homeCroc:{kind:string;period:number;active:number}|null` — Bay threat for this level, in milliseconds. - `lady:{lane:string;item:string;kind:string;period:number;active:number}|null` — Escort piece, in milliseconds. - `messages:Record` — Death messages by cause; empty means derived from the piece kind. ### `FroggerObject` ```ts type FroggerObject = LaneItem & { lane: string; row: number; phase: LanePhase; speed: number; role: 'vehicle' | 'platform' | 'hazard'; parts: number; } ``` A piece as sampled for collision, carrying and drawing: lane, row, activity phase, signed speed, role and drawn parts. ### `FroggerOptions` ```ts type FroggerOptions = { … } ``` Generation controls. Omit `board`, `rules` and `preset` for the classic arcade crossing. - `seed: number` — Unsigned 32-bit seed for counts, lengths, spacing and divers. - `difficulty?: 'easy' | 'medium' | 'hard'` — Speed multiplier (.8, 1, 1.13) and any per-difficulty lane counts and gaps; default `medium`. - `level?: number` — Starting level, 1 to `rules.levels`; default 1. - `lives?: number` — Frogs, 1–9; default 3. - `seconds?: number` — Timer seconds per frog, 10–300, or 0 for no timer; default 60. - `turtleSurface?: number` — Default seconds a diver stays surfaced, 3–12; default 5. Lanes may set their own. - `turtleUnderwater?: number` — Default seconds a diver stays under, .6–2; default 1.1. Lanes may set their own. - `preset?: keyof typeof froggerPresets` — A named design from `froggerPresets` supplying the board and rule defaults; default `classic`. - `board?: FroggerBoard` — The board, replacing the preset's. - `rules?: FroggerRulesInput` — Rule overrides, merged over the preset's rules. ### `FroggerOverlay` ```ts type FroggerOverlay = { … } ``` An extra lane laid over a row, such as a snake on the median or an otter in the river. Its pieces are hazards. - `row:number` — Row index it crosses: not the start row or the home row. - `from?:number` — First level it appears on; default 1. Needs `rules.hazards`. - `lane:FroggerLane` — Its moving pieces. ### `FroggerPiece` ```ts type FroggerPiece = { … } ``` One kind of moving piece. A lane uses its piece templates in turn: `[log, lily pad]` alternates them. - `kind:string|string[]` — Presenter name, a lowercase identifier (`truck`, `log-small`). Several names: each piece picks one by seed. - `length:number|number[]` — Physical length in cells. Several lengths: each piece picks one by seed; repeat a value to weight it. ### `FroggerPreset` ```ts type FroggerPreset = { … } ``` A complete design: a board and the rules that differ from the defaults. - `board:FroggerBoard` - `rules:FroggerRulesInput` ### `FroggerRow` ```ts type FroggerRow=FroggerSafeRow|FroggerLaneRow|FroggerHomeRow ``` One board row, listed bottom (start) to top (home). ### `FroggerRules` ```ts type FroggerRules = { … } ``` How a crossing plays. Every field has the classic arcade default. - `support:'footprint'|'centre'` — `footprint` (default): the whole frog must be on a surfaced piece. `centre`: only its centre point needs support. - `drift:number` — Cells the frog's footprint may ride past a side edge before the drift death; 0–2, default 0. - `bayTolerance:number` — Cells the frog's centre may land off a bay's centre and still enter it; 0–1.5, default .35. - `vehicleInset:number` — Cells trimmed from each end of every vehicle's hitbox; 0–1, default 0. - `radius:number` — Frog half-width in cells; .1–.45, default .23. - `hopSeconds:number` — Hop duration in seconds, .1–.4 in steps of .01; default .18. - `bufferHops:boolean` — A hop pressed mid-hop is queued and taken on landing; default false (rejected). - `hopCarry:boolean` — A hop from a moving platform keeps the platform's motion, so hops are relative to it; default false (hops are relative to the field). - `timer:'attempt'|'life'` — When the timer refills: `attempt` (default) — every new frog, after a death or a filled bay; `life` — only after a death. - `homeSpeedUp:number` — Fraction every lane speeds up per filled bay (compounding); 0–1, default 0. - `levelSpeedUp:number` — Fraction lanes speed up per level, cycling every `levelCycle` levels; 0–.5, default .065. - `levelCycle:number` — Levels in a progression cycle; 1–99, default 5. - `levels:number` — Levels in the game, 1–99, default 99. Filling every bay on the last level wins (`status: 'won'`); 1 makes a single-board game. - `hazards:boolean` — Level-gated hazards: lane swaps, overlay lanes and bay threats; default true. - `extraLife:number` — Score that awards one extra life; 0 for none. Default 20,000. - `score:FroggerScore` — Points awarded. ### `FroggerRulesInput` ```ts type FroggerRulesInput=Partial>&{score?:Partial} ``` Rules as a game supplies them: any subset, with `score` merged field by field. ### `FroggerSafeRow` ```ts type FroggerSafeRow = { … } ``` Solid ground: the start, a median, a verge. Overlay hazards may still cross it. - `kind:'safe'` — Row kind. - `name?:string` — Presenter name (`curb`, `median`). - `edges?:FroggerEdges` — Side edges; default `block`. ### `FroggerScore` ```ts type FroggerScore = { … } ``` Points awarded. - `hop:number` — Each safe landing; default 10. - `forwardOnly:boolean` — Award `hop` only for a row this frog has not reached since it last started; default false (every safe landing). - `bay:number` — Filling a bay; default 50. - `second:number` — Per whole second left on the timer when a bay fills; default 10. - `fly:number` — Collecting the bay bonus insect; default 200. - `lady:number` — Bringing the escort home; default 200. - `clear:number` — Filling every bay; default 1,000. ### `FroggerSearchError` ```ts type FroggerSearchError = Error & { furthest: number; stood: number; } ``` A search failure: the furthest row any explored route landed on, and the furthest row a frog could stay on for a hop. ### `FroggerSettings` ```ts type FroggerSettings = { … } ``` Resolved generation controls, stored in each definition so `next-level` and saves can regenerate it. - `seed: number` — Seed. - `difficulty: 'easy' | 'medium' | 'hard'` — Difficulty. - `level: number` — Level of this course. - `lives: number` — Starting frogs. - `seconds: number` — Timer seconds per frog; 0 for none. - `turtleSurface: number` — Default diver surface seconds. - `turtleUnderwater: number` — Default diver underwater seconds. - `board: FroggerBoard` — The board design. - `rules: FroggerRules` — Complete rules. ### `FroggerState` ```ts type FroggerState = { … } ``` Complete simulation state. `best` is the highest row this frog has reached; `lastCause` why the last frog was lost. - `course: FroggerDefinition` - `time: number` - `remainder: number` - `remaining: number` - `frog: Frog` - `lives: number` - `score: number` - `homes: boolean[]` - `status: 'playing' | 'level-complete' | 'won' | 'game-over'` - `respawn: number` - `deaths: number` - `flies: number` - `escorts: number` - `extraLife: boolean` - `ladyTaken: number` - `message: string` - `lastDeath: string` - `lastCause: FroggerCause | ''` - `lastHome: number | null` - `best: number` ### `FroggerTuned` ```ts type FroggerTuned=T|{easy:T;medium:T;hard:T} ``` A value that may differ by difficulty: one value for all three, or `{easy, medium, hard}`. ### `FrogHop` ```ts type FrogHop = { … } ``` A hop in flight. `carry` is the platform speed it keeps (cells/second) and `drift` the cells carried so far. - `fromX: number` - `fromRow: number` - `toX: number` - `toRow: number` - `elapsed: number` - `direction: Direction` - `carry: number` - `drift: number` --- ## For AI agents: Phaser AE Phaser AE (Agentic Edition) is how people make games with AI on phaser.io. 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