Add-On in poker is an option to buy extra chips in a tournament. It usually appears in rebuy tournaments and is often available at the end of late registration or during the first break.

The idea is simple: the player pays another entry amount and receives an additional stack. The key difference from a rebuy is that an Add-On does not require the player to lose all their chips first. That is what makes it a separate tournament feature rather than just another rebuy.

In practice, an Add-On helps a player move into the next stage of the tournament with a more comfortable stack. It can look like a strong value move, especially when the extra chips are offered at a decent rate and the structure is moving quickly.

In tournament poker, Add-On is a useful tool, particularly when short stacks lose value fast and survival starts to depend on stack depth.