King-maker scenario

A kingmaker scenario, in a game of three or more players, is an endgame situation where a losing player, him- or herself unable to win, has the capacity to determine which player among others is the winner. Said player is referred to as the kingmaker or spoiler. No longer playing for him- or herself, he or she may make game decisions to favor a player who was kinder to him or her earlier in the game.

Gladiator example

Consider this simple game: Three gladiators play, with strengths 3, 4, 5. In turn, each gladiator must engage another, and they begin combat. The result of combat is that the weaker player is eliminated, and the stronger player loses strength equal to that of the weaker player. (For example, if 5 attacks 3, 3 will die and 5 will become 2.) The winning gladiator is the last one standing.

Regardless of which gladiator he is, the gladiator with the first turn is the kingmaker.

Here's why: Each round of combat eliminating one gladiator, there will be two rounds of combat. The first round of combat will eliminate one participant and weaken the other to a strength no greater than 2. The nonparticipant's strength is at least 3, so he is guaranteed to win the second round of combat, and the entire contest. Therefore, the game collapses: The winning gladiator is the one not involved in the first battle.

Hence, the gladiator whose turn comes first is the kingmaker. He must be involved in the first battle, hence cannot win, but with the liberty of choosing his opponent in that battle, can elect either of the other two players to be the winner of the contest.

Kingmaker scenarios in practice

Because they allow the outcome of the game to be determined by a player of (presumably) inferior strategy, kingmaker scenarios are usually considered undesirable, though to some extent they may be unavoidable in strategy games. In these games, the players' outcomes and strategies are often so interconnected that to eliminate all possibilities of this situation is almost impossible.

In tournament situations, kingmaker situations can be especially corrupting, since a losing player may use this power to influence events beyond the scope of the game at hand. For example, if seating in future rounds is dictated by past performance, a losing player in this situation might use his or her position of power to place a weaker player at his or her table in subsequent rounds.

Different games deal with the kingmaker problem in different ways:

• In Puerto Rico, players conceal their victory point totals by overturning their hexagonal tiles, which could denote either 1 or 5 points. This ambiguity makes it unclear (unless players are especially attentive) which player is in the lead.

• In Monopoly, rules regarding behavior at bankruptcy serve to reduce the frequency of kingmaker situations.

• Most games prohibit, with penalties greater than match loss (for example, ostracization, disqualification) questionable or unsportsmanlike conduct geared toward effecting a kingmaker scenario.
  • Stalling, or intentionally slowing game play in timed games, for personal advantage or to that of a currently leading player, is normally treated as unsportsmanlike conduct.
  • The use of revokes, or intentional rules violations, in trick-taking card games, to void a round and effect a kingmaker scenario is discouraged by use of severe penalties. In tournaments, doing this can be classified as cheating.