How the grid plays
- Turns, not sweeps. Characters act in turn order. At the end of every character's turn the whole flock runs one square west or east. A party of six sees the flock move six times each round.
- Luck decides the direction. At the end of their turn, the player makes a luck check (d20, DC 11). On a success they choose which way the flock runs. On a fail the DM chooses.
- Rows and walls. Each Rapierhead stays in its row and wraps around when it reaches a wall. Every square is 5 feet, so the grid is 110 feet wide and 125 feet deep.
- Strikes. A Rapierhead that runs into a character's square, or whose square a character steps into, deals its damage. The standard is 1 piercing damage per strike.
- Sentinel. A character standing as Sentinel blocks the flock. The Rapierhead that would run into them stops and strikes them instead, and the birds lined up behind it stop too.
- Immobilised. An entangled or held Rapierhead stays put and blocks its row until released.
- Regeneration. A Rapierhead that is killed falls in a heap of feathers and rises again in the same square a couple of rounds later.
- The orb and the door. The top and bottom rows are safe. A character must touch the orb row and then return to the start row.