Light every open cell. Bulbs shine along rows and columns until a wall; bulbs must never see each other. Each numbered wall needs exactly that many adjacent bulbs.
Tap / Enter / Space — toggle a bulb.
× tool / right-click / X — exclude a cell.
Drag — paint; arrows — move; Z — undo.
Hint outlines a logical move and its evidence. Press Hint again to apply it. Marks can create contradictions; the outlined rule explains them.
Enlarge the board in Settings, then choose Pan to move it. Escape cancels an unfinished gesture. Undo restores the whole gesture.
Akari, also called Light Up, follows the pencil-puzzle rules published by Nikoli. These boards are original.