A strategic form of a game in game theory is generally a presentation in a table like the following:

                                          Coop          Defect
                                    +--------------+--------------+
                                    |              |              |
                              Coop  |   5  ,  5    |   -10 , 10   |
                                    |              |              |
                                    +--------------+--------------+
                                    |              |              |
                             Defect |   10 , -10   |   -5 ,  -5   |
                                    |              |              |
                                    +--------------+--------------+

That’s one version of the classic Prisoner’s Dilemma game in strategic form, also called normal form, where “Coop” means cooperate. The row player chooses either the top row (cooperate) or the bottom row (defect). The column player chooses either the left or right column.

The outcome of the game is the cell of the table selected by both the row and column chosen. The payoff in utility to the row player is the first number in the outcome cell, and the payoff to the column player is the second number.

The strategic form is used for games which are:

  • static, in that each player makes their move simultaneously, and only makes one move; and
  • finite, in that there's a finite number of moves per player, and a finite number of players.
For dynamic games, the extensive form is used.