See also the category disambiguation page.

Categories is a word game in which players think of words that begin with specified letters and belong to specified semantic categories. For instance, given the letters in "Sargon" and the category "U.S. states", one can list:

• South Carolina
• Arkansas
• Rhode Island
• Georgia
• Oregon
• North Dakota

A typical game consists of choosing five initial letters and five categories. These become the rows and columns of a 5×5 grid which the players attempt to fill within five minutes. If there are only two players, the one who fills more of the 25 combinations is the winner. If there are more than two players, the scoring usually discounts any entries written by more than one player.

Categories is related to the commercial games Scattergories and Facts in Five.

Categories is also a party game in which players think of instances of a specific category. The players typically sit cross-legged in a circle and collectively establish a rhythm of six beats: slap slap (on the thighs), clap clap, snap snap. The players speak in turn clockwise around the circle on the snap beats, using the slap and clap beats to gather their thoughts. On a player's turn, he or she must name a new instance of the category or be eliminated. Eliminated players sit out, creating an ever-shrinking circle, until only one player remains.

Typically a category is not chosen in advance, but is specified by the third player to speak after the first player has said "Categories" and the second player has said "such as...". A demonstration game between five players will illustrate:

slap slap clap clap - Player 1: "Categories"

slap slap clap clap - Player 2: "such as..."

slap slap clap clap - Player 3: "Diseases" (everyone now knows the category)

slap slap clap clap - Player 4: "Cancer"

slap slap clap clap - Player 5: "Chickenpox"

slap slap clap clap - Player 1: "Measles"

slap slap clap clap - Player 2: "Athlete's foot"

slap slap clap clap - Player 3: "Mistletoe" (this is not a disease; Player 3 is eliminated)

slap slap clap clap snap snap (Player 4 is laughing so hard at Player 3 she misses the beat and is eliminated)

slap slap clap clap - Player 5: "Tuberculosis"

slap slap clap clap - Player 1: "Schizophrenia"

slap slap clap clap - Player 2: "AIDS"

slap slap clap clap - Player 5: "Ebola"

slap slap clap clap - Player 1: "Emphysema"

slap slap clap clap - Player 2: "Herpes"

slap slap clap clap - Player 5: "Hiccups" (getting desperate, but the other players accept it)

slap slap clap clap - Player 1: "HIV" (this is considered a repetition of AIDS; Player 1 is eliminated)

slap slap clap clap - Player 2: "Malaria"

slap slap clap clap - Player 5: "Leukemia" (considered a repetition of Cancer; Player 5 is eliminated; Player 2 wins)

A common variation is to play each category only until the first elimination. After an elimination there is a short pause, after which the player who was due to speak next restarts the game by saying "Categories". In this variation, no category may be chosen twice. The advantage of this variation is that there is sometimes contention over whether a player should be eliminated, and the pause allows for calm discussion of whether, for example, hiccups is really a disease. The disadvantage is that players are less often required to speak several times in the same category.