hold a card of specific face value, one of which the builder already knows resides in their own hand. The value of building decreases significantly as the number of players in the game increases. In a two-player game, one requires only one adversary to be bereft of the necessary cards; in a four-player game, one requires three adversaries to be lacking the necessary cards to steal a build. As such, building effectively in a two-player game can be very advantageous, but in a four-player game is very difficult. Acting with builds on the table At least three rule variants exist dictating the actions which may be taken by a player who has a build on the table: Variant 1: a player with a build on the table is not permitted to trail a card until that build has been taken in or rebuilt upon by an adversary; they may, however, pair or continue their "build" with any card on the table. Variant 2: a player with a build on the table is obliged to either take in that build, by pairing or combination, or to add to that build on their next turn. Variant 3: A player with a build on the table cannot trail. Play must initiate from the hand. Continuing a build from only cards on the table is not allowed. You must either take in the build, duplicate it or increase it, OR defer by starting another build or assuming ownership of an opponent's build. A build 'belongs' to the last player that set its value. You may assume ownership of a build started by another by increasing it. But only if it consists of a single combination, i.e., not duplicated. You may have more than one build, but only one of any particular value, and having a build of the same value of another (an adversary's) makes no sense at all. While Hoyle recommends variant 1, all variants are very common in different regions. The regional variant of this rule in particular should always be checked before play. Which variant is used changes the tactics, particularly in a two-player game. Under variant 1, the builder has a profound advantage; if they know that their adversary lacks the cards necessary to steal their build, they can often take several cards trailed by their adversary before taking in their build at the end of the round. Variant 2