Are there many larp groups in the world?
Larp exists in Europe, the USA, Israel, South America and New Zealand. Within the UK, there are larp groups running games ranging from sci-fi action to Victorian horror. The biggest larp group in the UK has around 3000 members. For an example of a UK system which many Treasure Trap members also play in, see this link: http://www.profounddecisions.co.