◀ 11.512.1a12.1b ▶

12.1a — Grid/Symmetry Jam: Kickoff & Pitch

The exam is behind you. The games are not. Third jam, and the constraint is structural this time: a GRID with SYMMETRY — the design language of Tetris, Picross, chess, Snake, Minesweeper. When the grid is the rule, every design decision multiplies.

Kickoff ~15 min

What the constraint means:

Grid: movement, placement, or both snap to cells — think in indices, not coordinates (your 7.1 tilemap was a grid you PAINTED; this one you PROGRAM)
Symmetry: the game state, the board, or the CONTROLS mirror somehow — vertical (chess: both sides same), rotational (Tetris: each piece is its own mirror), or player-vs-player (both play identical rules)
Either half may dominate: a grid game with light symmetry, or a symmetric duel on a grid

You have already done grid math without noticing: your hand of cards rendered by index (10.2c — position = index × spacing). A grid is that, in two axes: x = column * cellSize. The symmetry half? Your turret personalities (3.4) were mirrored difficulty — same idea, one axis up.

Socratic

Symmetry is a GENERATOR: define one half, mirror it, get the second half free. Where in code does that save work (spawn positions? level halves? an AI that plays YOUR OWN rules — like your card AI (10.2d) but as player two)? Which symmetry would make your game's content FREE?

Your answer

Pitch & Vote ~30 min

Pitch card (10 min):

One sentence: "a grid game where ___ is symmetric because ___"
The core loop: one move, its consequence, why it repeats
The symmetry's JOB: fairness (duel)? difficulty (mirror match)? beauty (pattern play)? — name it
Reused-parts list (10.1a rules: honest inventory)

30-second pitches → votes → teams of 1–3 (same contracts as every jam). This is the last new-team formation of the year: choose for who you work WELL with, not who you sit near.

Checkpoint — before moving on, you must be able to:

Name three real grid games and their symmetry type
Pitch a grid+symmetry loop in one sentence
Define the input → grid mapping in your README

Reference Docs

Need a deeper explanation? These pages cover the same concepts:

Lists & Arrays — a grid is a list of lists
Unit 12: Season 2 — the last jams

Next: 12.1b — Grid/Symmetry Jam: Build Day 1

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