Boffer LARP is my specialty. If it's a story you need, then come if you can to Stella Olsen Park in Sherwood on either Wednesday or Friday between 3 and 5 PM. Or for all the LARPing you can quaff, come to the Halloween party at Rivercrest Park in Oregon City. The chapter there almost always has a game, and I heard they might be doing a monsters game.
This group, called Amtgard, is more than welcome to let curious spectators watch or pick up a weapon and jump into a game. Waivers are signed by potential regular attendees to cover for accidents. There is a full set of rules covering the basic combat rules, weapon and shield sizes and types of armor, classes and their abilities or spells, as well as some starting creatures for someone playing the Monster class. Players get to make and cosplay as their own original characters and only their own strength, speed, and skill will determine that character's developing proficiency.