All Fours is a trick-taking card game, usually played with four players in two-player partnerships, that dates from around the 17th century. There are many rules variations, but the version implemented on Board Game Area as Caribbean All Fours is meant to be an adaptation of the modern game as it is played in Trinidad and Tobago.
The game plays as described in the "Rules of Card Games" website under the heading "All Fours in Trinidad": link, with the following differences:
- No misdeal: since the game software deals the cards, there is no possibility for a misdeal, no points can be scored for this scenario
- No revoking/reneging: for simplicity of online gameplay, playing cards illegally is not allowed, and therefore revoking is not necessary
- High -- 1 point This point is won by the team of the player who had the highest trump.
- Low -- 1 point This point is won by the team of the player who held the lowest trump that was dealt. It does not matter who wins the trick containing this trump - the point is for the original holders.
- Jack -- 1 or 3 points If the jack of trumps wins a trick, or is won in a trick by the partner of the holder, the team with the jacks scores 1 point. If the jack is captured in a trick won by the opponents of the holder, the team capturing the jack scores 3 points for hang jack. If the jack of trumps was not dealt, then of course neither team scores for it.
- Game -- 1 point This point goes to the team that wins the more valuable cards in tricks. For this purpose only, the top five cards in each suit have the following values: ace = 4, king = 3, queen = 2, jack = 1, ten = 10; other cards (2-9) have no value. Each team adds up the total value of the cards in their tricks, and whichever team has more scores the game point. If both teams have the same value of cards, no one gets the game point.
The only variation implemented at this time is the alternate trump scoring as played in Tobago (a Two scores two points when turned instead of a Six)