/blog/how-culling-worksHow culling works
The cull is the heart of CULLS. Everything else — the placement, the five-in-a-row, the back-and-forth tempo — is in service of the moment when you close a bracket and your opponent watches their chips flip. Here's exactly how that mechanic works, every edge case included.
The pattern
A cull fires when your placement creates a four-cell window in a straight line that reads YOU · OPP · OPP · YOU, with your just-placed chip at one end. The two opponent chips between are culled.
All three axes count
Each cell has six neighbours, organised along three axes: the horizontal one, and two diagonals. Any of the three axes can carry a cull, and a single placement is checked against all three.
You can cull more than one pair on a single move
If your placed chip is at the end of bracket A on the horizontal axis and at the end of bracket B on a diagonal, both brackets fire. You'll be prompted to pick the trapped chip for each one, and both pairs are removed at the end of the turn.
The flipped chip lingers
This is the design decision that most often surprises new players. When you cull a pair, the chip you pick doesn't vanish immediately — it flips face-up to show the CULLS “C” mark, and stays in place for one full opponent turn before sweeping off.
Why? Two reasons. First: it makes the moment of the cull legible. The opponent has time to look at the board, see what just happened, and plan around it. Second: it prevents a particular form of opacity in fast online play, where moves and counter-moves can blur together. The flipped chip is a frozen frame.
The starting-turn exception
On each player's very first turn they place two chips back-to-back. Even if those four placements happen to form the bracket pattern, no cull fires. Regular play — and the cull rule — begins once both players have completed their starting turns.
The “self-cull” non-rule
People new to CULLS sometimes ask: “what if I place between two opponent chips — do I cull myself?” No. The cull rule is scanned only from the placing player's perspective and only removes opponent chips. Placing into the middle of an opponent's pair — making the pattern OPP · YOU · YOU · OPP from their perspective — is perfectly legal. It's also dangerous: they can close the bracket on their next turn and cull you.
What you can do with this
- Set traps two moves out. A cull is much harder to spot when one of the two end-chips isn't placed yet. If you can lure your opponent into the middle, you can close the bracket later.
- Cull to win. Sometimes the cull isn't about removing material — it's about opening a row for your own line of five. Detection runs after culls resolve.
- Don't be greedy. Every chip you place to extend a bracket is also a chip the opponent can target. Capturing a single pair at the cost of a five-in-a-row threat is rarely worth it.
For the strategic patterns built on top of this mechanic, head over to the CULLS strategy guide.