American freeform is a tradition of small, focused larp which evolved from Jeepform, Danish freeform, Nordic larp, theatre-style larp, and tabletop indie RPGs. It differs from theatre-style in that it is only semi-live; some parts may be closer to a tabletop rpg, and it may use significant GM or player narration. It differs from Jeepform in having an emergent rather than set narrative. It differs from Nordic larp and Danish freeform in that it is specifically American.
American freeforms tend to be small and short, with between 3 and 12 players and lasting no more than four hours (with two being more typical). They tend to use scenes and metatechniques. At the edges, some American freeforms (e.g. JUGGERNAUT) are indistinguishable from theatre-style larp, while others are indistinguishable from a tabletop freeform game.