The rook attacks in straight lines: up, down, left, and right. Its beam travels any distance until it hits the edge of the board, another piece, or an obstacle.
Self-lighting
The rook lights its own square plus every square along its row and column, stopping at the first blocker in each direction.
World interactions
Different world mechanics change how the rook behaves:
Blocked cells: Blockers stop rook beams. A rook on one side of an obstacle cannot reach targets on the other side.
Enemies: Enemy-occupied squares block rook beams just like obstacles. Plan your line of fire around the sentries.
Portals: A rook beam entering a portal exits the paired portal traveling in the same direction (still orthogonal).
Reflection: Rook beams are orthogonal, so they are not affected by Beach's diagonal reflection. Only bishops and queens benefit.
The rook covers the most squares on an open board. Place it where its row and column intersect the most targets. Watch out for obstacles that split its coverage into disconnected segments.