Espionage requires at least two (possibly more) teams of three people each, plus at least one referee. The most unusual part of the game is that the players don't know which team they are on. Teams change with each round.
The game is traditionally played at night in a home and the surrounding yard. At the beginning, before the first round, players are taken around and shown a large number of places (locations) and objects. Locations include some inside the house and some outside.
When a round starts, one or more kids are chosen to be the referees (which can be more fun than being on the teams). The referees get together in a room, determine who will play each role on each team, and then invite each other player in one at a time to tell them what they need to know. Once everyone is told, the referees start the round with an invocation (prayer) and turn out the lights.
Each team has three roles. The Captain knows two locations, the meeting place and the jail, plus a password. The meeting place is always inside and the jail is always outside. The Captain may arrest players by touching them while saying "I arrest you". Captains are immune to arrest. Once arrested a player may not speak and must go with the captain to the captain's jail. The player must remain there until touched by a player who says they are free.
The mate knows two locations, the meeting place and the goal, but not which is which.
The yeoman knows an object (the totem), the password, and the jail(s) of the other team(s).
The purpose of the game is to get the totem to the goal. Success requires identifying the other members of your team (no small feat). Once you have done so, the mate or yeoman, but not the captain, may pick up the totem and move it to the goal. The captain must then call out that his team has won. The referee(s) then turn on the light and check the claim. Incorrect claims mean the captain's team loses, while correct claims win.
This is a game with many opportunities for winning by deluding the other team into thinking you are part of their team.
This is supposed to have created by a secret society with threats to prevent members from telling. Girls were supposed to be forbidden to play (though we always played with them).