Presentation by Ken Clary of the MIT Assassin’s Guild, at NELCO 2014. Abstract here.
This is a really good presentation on the philosophy of (theatre-style) larp design. TLDR: Larps let you be a character. RPGs (and therefore larps) are about choice, in larps in particular story is emergant and out of control of the GM, so embrace this. Write a complex web of conflicting goals and tension and let the players go wild. Keep mechanics simple, and don’t waste people’s time with them.