How to Play LITS
Place one tetromino (L, I, T, or S shape) in each region so shaded cells are all connected, no 2×2 block is fully shaded, and identical tetrominoes are never adjacent.
Try it now — Easy 7x7 →The Rules
- Choose one tetromino shape (L, I, T, or S) for each region and shade exactly 4 cells in that shape
- All shaded cells across the entire grid must form one connected group
- No 2×2 block of cells may be entirely shaded
- Two tetrominoes of the same letter (same shape) cannot share an edge
Available in 3 sizes (5x5, 7x7, 10x10) and 3 difficulty levels (easy, normal, hard).
See It in Action
Shade one L, I, T, or S tetromino per region — all shaded cells must form one connected group
How to Play
- Identify regions where only one tetromino orientation fits — place those first
- Ensure adjacent regions' tetrominoes connect to each other to maintain global connectivity
- After each placement, check the no-2×2 constraint and the same-shape adjacency rule
- Work outward from forced placements to resolve remaining regions
Pro Tips
Small or oddly-shaped regions have very few valid tetromino placements — start with those
The I-tetromino can only be placed in two orientations — use this to quickly rule out invalid positions
Global connectivity is the strongest constraint: isolated tetrominos separated from the main group are illegal
Frequently Asked Questions
What is LITS?
LITS is a logic puzzle where you shade a tetromino (4-cell shape) in each region. All shaded cells must be connected, no 2×2 area can be fully shaded, and two identical tetrominoes (same letter) cannot share an edge.
Choose Your Challenge
Start with easy to learn the rules, then progress to harder difficulties.