Party games are games suitable for entertaining in social gatherings. Though the definition is not strictly set, party games tend to include many or all of the following traits:

• The game supports a relatively large or undefined number of players, compared to more traditional board games or card games that require a small, set number of players. Some games, especially commercial games, have a set limit based on available equipment; others are limited by other mechanics of the game like time for each turn, while still others have no practical limit.
• Team-based play in party games is common, but not required. Games that divide players into two, three, or four roughly equal teams, such as Cranium, Charades or Pictionary tend to allow for larger total numbers of players. By contrast, other games such as Werewolf and How To Host A Murder are role-based, with each player being given a character or other role to play in the course of the game. The number of players is limited to the number of roles, but in many such games there are "generic" roles allowing for a high degree of flexibility.
• Cooperation and interaction between many players at once is encouraged. Both team and role-based play generally encourage this social aspect to the game; games that do not encourage this interaction generally make poor party games.
• Multiple ways to play and contribute. For example, in Fictionary not everyone needs to create plausible dictionary definitions; humorous submissions are welcome. In Charades, players can actively participate in guessing without taking a turn at acting. Sports often make poor party games as limitations in a player's physical abilities may preclude participation; however, some popular party games like relay races or Red Light/Green Light involve a significant physical aspect and are especially suitable for groups similar in age and ability.
• Players participate in gameplay frequently, sometimes on an impromptu basis. Games in which each player has their own independent turn generally make poor party games, especially if a turn takes a long time.
• The game has entertainment value for spectators. Many party games involve at least some level of humor, whether inherent in the game or introduced by players. In this way, players not taking a turn can still enjoy the gameplay.
• Player elimination is rare. Monopoly makes a poor party game, because bankrupt players must sit out while the remaining players continue to the game's conclusion, which can take several hours. In contrast, no matter how far behind a team is in Pictionary, all players can participate until the very end.
• The amount of specialized equipment needed is not dependent on the number of players. Games such as Liar's Dice make poor party games because each player needs a cup and five dice to start the game. By contrast, Yahtzee needs only one cup and set of dice regardless of the number of players (the basic Yahtzee game does have other practical limitations).
• The game usually does not involve spending real money as a prerequisite or consequence of playing. Games that require each player to purchase consumable items or specialized equipment are usually poor party games. Casino games are a notable exception; a "casino night" with a token door charge or buy-in for charity or to defray costs can be popular, as can poker tournaments with a similar small buy-in.