Sardines is the best group hide and go seek game ever! It was a super fun game to play when I was a child and all of my children still play it now. It works great outdoors or indoors. You do need at least 4 people to play. This is a great last minute game at birthday parties.
Here is how you play Sardines:
One person is 'IT' and he/she goes and hides.
Everyone else counts to 50. Everyone then starts to look for the person who is hiding. If you find him/her, you hide with them quietly. As each person find the person who was 'it', the hiding spot gets more and more crowded. Once everyone finds the hiding spot, the first person who found the hider is it for the next round and gets to hide first.
I think the reason the kids enjoy it so much is because there is a hint of fear with this game. You start out with everyone looking, but sooner or later you may be alone and the only person hunting for everyone else. It is great childhood fun!
Need more group game ideas? Check out Set the Record.