What is LITS?
LITS is a shading logic puzzle played on a grid divided into irregular regions. Your job is to shade one tetromino in every region, using only the L, I, T and S tetromino shapes.
The O tetromino is not used because it would create a forbidden 2x2 shaded block. A good LITS puzzle has one logical solution, so the challenge is deduction rather than guessing.
- Shade exactly four connected cells in every region.
- The four shaded cells in a region must form an L, I, T or S tetromino.
- All shaded cells must join into one connected area.
- No 2x2 block may be fully shaded.
- Matching tetromino types may not touch horizontally or vertically, even when rotated or reflected.
How to play LITS online
Choose a grid size and difficulty, then shade cells until each coloured region contains one legal tetromino. The board checks the full LITS rule set, including region shapes, 2x2 blocks, connectivity and matching shapes touching.
Small 6x6 LITS puzzles are best for learning the rules. The 8x8 and 10x10 boards give more room for connected-shading logic and harder shape choices.
- Tap a cell to shade it.
- Tap it again to clear it.
- Use Check to highlight current rule problems.
- Use Undo to step back one move.
- Use Solution only when you want to reveal the unique answer.
LITS solving strategies
Start inside the regions. If a region has only a few possible tetromino placements, compare them with neighbouring regions and remove any placement that creates a 2x2 shaded square.
Next, think globally. The shaded cells must form one connected group, so isolated tetrominoes are suspicious unless another region can connect to them later. Matching shapes touching edge-to-edge are also a strong source of eliminations.
- List the possible L, I, T and S placements in tight regions.
- Eliminate any placement that completes a 2x2 shaded square.
- Watch for same-shape neighbours across region borders.
- Keep the shaded cells connected as the solve develops.
- Use forced regions to limit the shape choices nearby.
Grid sizes and difficulty
This LITS game includes 6x6, 8x8 and 10x10 boards. Easy puzzles keep the candidate shapes tighter, medium puzzles add more cross-region choices, and hard puzzles make you track connection and shape-touching rules for longer.
Every built-in puzzle has been checked by a solver for a single solution. That uniqueness check is expected for LITS because multiple solutions would make the puzzle feel ambiguous.
- Easy: smaller boards and more direct region deductions.
- Medium: more candidate shapes and connected-area reasoning.
- Hard: larger regions, fewer immediate placements and deeper eliminations.
Why play LITS here?
This free LITS online page is built for quick play: no signup, bright region colours, multiple grid sizes, undo, checking and a readable strategy guide underneath the game.
If you searched for play LITS online, free LITS puzzle, LITS game, LITS rules or LITS strategy, this page gives you the playable puzzle and the rule explanation in one place.