Kicker

The highest card in your five-card hand that is not part of the pair, trips or other combination — used to settle a tie when two players hold the same ranked hand. Ace-king and ace-four both make a pair of aces; the king is the kicker that wins.

As many as needed, up to five cards. With one pair, the three remaining cards are compared in order until one is higher; if all five cards are equal in rank, the pot is split, since suits never break ties.

Because weak-kicker hands like ace-rag make a top pair that looks strong and is frequently second best. Most of the money lost by inexperienced players in Hold'em goes into pots where they were dominated by a better kicker.