The Fifth Column is a precursor of Schotten Totten played with a standard deck of cards. In the basic version each player gets a hand of six cards and two rows of nine cards each are placed on the table to start the players' columns. Two cards are discarded and the rest form a draw pile.
On a turn a player plays to one of their nine columns, claims columns if possible, and draws a card. The three-card column sets are ranked from straight flush down. A column can be claimed even if the opponent's set is incomplete if you can prove there is no way they can beat your set. If a column is completed on both sides and is tied, the player who played last loses it.
The object is to claim five columns.
Some variants are given:
Ignore straights and straight flushes.
Each player gets 15 cards at the start and never draws any more.
Don't place any cards in the columns initially, as in the later game.