Sudoku and LITS are both grid-based logic puzzles you solve by pure deduction, so solvers naturally wonder how alike they really are. The short answer: LITS is distant to Sudoku. Below we lay out what the two share, where they part ways, and whether the skills you have built on Sudoku will carry over.
- Grid: Rooms grid
- Closeness to Sudoku: Distant
What is LITS?
Shade one tetromino in every region so all shaded cells connect, no 2×2 is filled, and touching tetrominoes are never the same shape. Here are the rules in full:
- In each region shade exactly four connected cells forming an L, I, T or S tetromino.
- All shaded cells across the grid connect into one group with no 2×2 fully shaded.
- Two tetrominoes of the same shape (rotations and reflections count) may not share an edge.
See a LITS region
LITS asks you to shade exactly one tetromino — an L, I, T or S shape — in each region, so all shaded cells connect, no 2×2 is filled, and touching tetrominoes are never the same shape. Below, an L-tetromino shaded inside one region.
One L-tetromino (four shaded cells) placed inside a region.
Both carve the grid into regions and reason under strict local rules, and the "same shape can't touch" rule rhymes with Sudoku's no-repeat neighbours. But you shade tetrominoes rather than place digits, and connectivity and the no-2×2 rule have no Sudoku equivalent — a distant relative.
What LITS shares with Sudoku
- Both carve the grid into regions and reason under strict local rules.
- The "same shape can't touch" rule rhymes with Sudoku's no-repeat neighbours.
How LITS differs from Sudoku
- You shade tetrominoes, not place digits, and most cells stay empty.
- Connectivity and the no-2×2 rule have no Sudoku equivalent.
Do Sudoku skills transfer?
No digit technique applies, but the case-by-case "which shapes fit here, and which are ruled out?" reasoning is close cousin to candidate elimination.
The verdict
LITS shares Sudoku's region logic and no-touch instinct but builds a tetromino mosaic, not a number grid.