419.1. A player Plays cards by placing them on the chain and queuing them to be finalized. See rule 349. Playing Cards for more information on playing cards. See rule 337. Finalize for more information on finalizing cards.

419.2. This is a Discretionary Action.

419.3. Game effects may result in cards being played as part of their resolution.

419.4. Some Abilities trigger when cards are played or otherwise check whether cards have been played.