NEVER Do (Expert Anti-Patterns)

NEVER punish experimentation; strictly provide Undo/Reset functionality to allow risk-free hypothesis testing.
NEVER require pixel-perfect input for logic puzzles; strictly use Grid Snapping or large, forgiving hitboxes.
NEVER allow undetected Soft-Locks (unsolvable states); strictly notify the player or provide immediate backtracking.
NEVER hide the rules of the world; strictly ensure visual feedback is instant and unambiguous (e.g., powered wires must glow).
NEVER skip the Non-Verbal Tutorial phase; strictly introduce mechanics in isolation before combining them.

NEVER use floating-point numbers (Vector2) for grid coordinates; strictly use Vector2i to prevent precision drift.
NEVER use _process() for grid-state or win-condition validation; strictly trigger checks only when a piece moves.
NEVER rely on the SceneTree structure as the source of truth; strictly maintain grid data in a separate script/dictionary.
NEVER modify a Dictionary or Array size while iterating over it; strictly use a copy or a separate queue for modifications.
NEVER calculate heavy recursive solvers in _process(); strictly cache results or use threaded workers for solve-checks.
NEVER ignore diagonal rules in pathfinding; strictly configure AStarGrid2D.diagonal_mode correctly.

godot-genre-puzzle