# Mr. Brick Adventures

A 2D platformer. This context covers **player state and progression** — what the player has, what they have done,
and at what point each of those becomes permanent. Gameplay behaviour (movement, combat, hazards) lives in the
composable components and is deliberately outside this context.

## Language

### Scopes

Three lifetimes. Every fact in this context belongs to exactly one.

**Attempt**:
One try at a level, from entering it to either completing it or losing a life. Holds a ledger of everything that
happened during the try — coins found, coins spent, skills bought. Discarded whole if the player dies.
_Avoid_: Session, run, life

**Playthrough**:
One game from New Game until game over, identified by a `PlaythroughId`. Holds lives, banked coins, owned skills
and their levels, campaign position, and which levels it has cleared. Several exist at once and the player picks
between them.
_Avoid_: Save, save slot, progress, game, run

**Profile**:
Everything shared across all Playthroughs, one per installation. Achievements, best time per Level, and lifetime
statistics. Never reset by starting a new Playthrough.
_Avoid_: Global state, meta, persistent data, account

### Operations

**Commit**:
Applying an Attempt's ledger to the Playthrough. Only a First Clear commits — nothing else, ever.
_Avoid_: Save, persist, flush, sync

**First Clear**:
Completing a Level this Playthrough has not cleared before. The only event that commits an Attempt and advances
campaign position.
_Avoid_: Level complete, finish (both ambiguous — they also describe a Replay)

**Replay**:
Completing a Level this Playthrough has already cleared. Records Best Time, achievements and statistics to the
Profile; commits nothing and never advances campaign position.
_Avoid_: Practice, retry, second run

**Bank**:
The coins a Playthrough holds, as opposed to coins found in the current Attempt. Coins are banked by committing,
never on pickup.
_Avoid_: Total coins, saved coins

**Discard**:
Throwing away an Attempt's ledger — on death, or at the end of a Replay. Purchases made during the Attempt are
undone by discarding, not refunded; under the ledger they never happened.
_Avoid_: Reset, rollback, revert

### Things

**Level**:
One playable stage, identified by a stable `LevelId` — never by position in a list. Knows its scene and display
name. Ids must survive inserting and reordering levels, because Playthroughs and Best Times both reference them.
_Avoid_: Stage, scene, level index

**Cleared Levels**:
The Levels a Playthrough has completed at least once. Gates both campaign progression and level select; whether a
Level is reachable is computed from this, never stored alongside it.
_Avoid_: Unlocked levels, completed levels, available levels

**Skill**:
An ability the player can own and upgrade. `SkillData` is the authored asset describing one (name, icon, upgrade
table) and is immutable at runtime; the level the player has reached in it belongs to the Playthrough.
_Avoid_: Ability, power-up, upgrade (for the skill itself)

**Movement Ability**:
A composable behaviour attached to the player controller (jump, wall-jump, gravity). Unrelated to Skill —
authored per movement preset, not owned, not upgraded, not persisted.
_Avoid_: Skill, movement skill

**Best Time**:
The fastest recorded completion of a Level, from a First Clear or a Replay alike. Belongs to the Profile, so it
survives New Game and is shared by every Playthrough. Stored alongside, but distinct from, the ghost replay
frames that produced it.
_Avoid_: Personal best, high score, record

## Rules

- Reads may cross scopes freely — affordability spans Attempt and Playthrough. Writes must not.
- Derived facts are computed, never stored. Level reachability is derived from Cleared Levels; total coins from
  Attempt plus Bank. Storing either alongside its source creates the second source of truth this context exists
  to prevent.
- Achievements are mirrored to Steam, which is per-account and cannot be un-earned. That is why they are Profile
  and not Playthrough: a per-Playthrough achievement list would contradict Steam permanently.
- Nothing in this context may reference Godot. Its correctness must be checkable without a scene tree.