Light Up

How to play

Put bulbs on the white squares until every white square is lit. A bulb lights its own square and shines along its row and its column until a wall or the edge of the board stops it. No bulb may stand in another bulb's light. A wall with a number on it has exactly that many bulbs against its sides, counting only the four squares it touches edge to edge, and a wall with no number tells you nothing. The two halves of the game pull opposite ways: lighting everything wants the bulbs spread out, and no two in sight of each other means no two share a corridor. Marking the squares you have ruled out is usually what makes the next bulb obvious, and a wall wanting none is often the most useful clue on the board.