Select a playing area, and set boundaries (e.g. certain landmarks, such as trees, or a roped-off perimeter). The more guests you have, the bigger the playing area should be.
Choose one guest to be the tagger (i.e. "it").
To start, the tagger should stand at the center of the playing area while everyone else stands along the edges or in a group on one side.
When you say, "Go," the tagger should try to tag as many of the other players as possible while the other players run to avoid being tagged.
As players are tagged, they must "freeze," holding the position that they were in when tagged.
Frozen players cannot move; if they do, they are out for the rest of that round.
A tagged player can only move if he or she is unfrozen by any other player.
The game is over when all players have been frozen. The last player to be frozen is it for the next round.
The game is over when all but one player has been frozen. The remaining player is it for the next round.
Select one child to be an "unfreezer" for every 3-4 players participating, OR select just one unfreezer for the entire round. Tagged players can only be unfrozen by an unfreezer. If you are playing with multiple unfreezers, they cannot unfreeze each other if one or more of them is tagged. You may want to implement this rule to prevent game play from becoming overwhelming for the player who is it.
For very small groups (3-5 players) where the player who is it has an advantage, make a rule that tagged players may be automatically unfrozen after 60 seconds. This provides the player who's it with a challenge-to freeze all players in under one minute.