A safe discard is a tile that is unlikely to help any opponent complete a run or set.

Good candidates include tiles whose matching numbers or neighbouring colours have already been discarded, and tiles no one has picked up. Late in a hand, throwing a tile that a player just declined is often safe. Try to avoid discarding tiles that pair with an opponent's recent pickups. Balancing safety against your own progress is key: sometimes you must hold a useful tile a turn longer rather than feed the leader.