If this is the last card in their hand, the round is over. A player must always end their turn by placing a card from their hand face up on top of the discard pile.After a player lays down their phase, they can play on phases completed by other players in subsequent turns.
A card can also be played on a colored set so long as it is of the same color. For runs of ordered numbers, this means playing a card whose value is either one below the lowest number in the run or one higher than the highest numbered card. One person can be skipped each round, meaning they can. In a set of cards, this means playing a card of the same number as the set. You keep ten cards in hand at all times until you lay down your phase. Playing on a phase means playing a card that is valid for that phase.They cannot play on a phase laid down by another player on the same turn they played their phase. When a player lays down their phase, they may also 'play' on the phase.The entire phase must be played at once, so if the player is on the 1st phase, they must play 2 sets of 3 cards at once.