Most fantasy LARPS use their own homebrew rules. Ours is pretty rules lite. Their really isn't a resolution system per se. If I hit you with a sword and am dealing two points of damage, you get hit for two points of damage. If you want to pick locks, you need to take the lockpicking skill which then allows you to physically attempt to pick the lock (we use luggage locks which are easy to pick for people with practice). Spells are delivered via tag bags (bean bags). You get hit, you take the effect of the spell. No saves, no dice, no rock/paper/scissors, no coin tossing, no cards, just skill.
__________________
"You'll be hearing from my rules lawyer!" - tetsujin28
On the non-Boffer side of the LARP world, there's mostly the Mind's Eye Theatre system for the World of Darkness games. There's Chthulu Live, the COC LARP, which is really nifty, but resource intensive. There's also a system called Rules to Live By that's a generic, somewhat GURPSesque LARP system. Then there's Passion Play (the Fading Suns LARP) and Castle Falkenstein is relatively easy to play LARP style, either with every player carrying a pack of cards, or with a number of referees with cards to handle challenges as they arise.
There was another vampire LARP that came out a little after MET first did - using a far more narrative system (ie, just figure it out yourself) and a different mythology/vampire society. I played once, it was okay.
I'm probably missing a few, but those are the ones I know.
In terms of popularity, there's MET, which stands head, shoulders, torso, knees, and toenails above anything else, then probably a smattering of those other games.
Which is too bad. I would LOVE to play a Passion Play LARP.
In general, LARP systems are either tabletop systems for which you stand up and walk around (MET, Nobilis LARP) or they have resolution mechanics based on physical actions and OOC skill (like, for example, Lorien Trust or Maelstrom).
I consider the latter type more interesting and fun (if I want to use a tabletop-style system, I'll play tabletop). The problem with LARP systems in general is that they aren't generally as well developed as tabletop systems - possibly because there's not as much money in LARP as in tabletop design. Well... Maelstrom system could be very well developed but I wouldn't know if it were, because the players are not told nearly all the rules.
And yes, most little LARP groups use their own homebrew rules sets. Everybody thinks they're a game designer. Sigh.
__________________
Running Cthulhutech: Transcendent Metamorphosis: SALVATION
Running 4e: Xanadu
Playing C:tD: Thomas d'Auvergne, the best knight in Brittany
Cosmic Truth points: 1 and counting-without-counting
Oh, you asked for an example system, didn't you. Here's the one for the larp I take part in.
The basic combat mechanic is quite simple. Your skills allow you to call an amount of damage for each hit with a (approved, safe) weapon - for example, 'Single' or 'Double'. Each location of yours (arms, legs, torso, head) has a number of hitpoints (usually 4 for torso/head and 2 for arms/legs, though skills may change this). Battle is resolved in the obvious way. There are subtleties involving armour (adds hitpoints) and damage types (ignore certain armour types).
Magic and priestly miracles are as follows. You speak a verbal component of at least 8 + [spell/miracle level] words, ending in the name of the spell or miracle and any mechanical effect it has - for example "Let the power of the mighty element of fire strike you! Fireball! [target descriptor] Magic Flaming Three!", where the words after 'Fireball!' were an OOC call telling everyone who the target was and what had happened to them. The experience system is level based (but not class based; it's somewhat of a bodge), and one's experience level determines one's resistance to certain miracles.
Generally, there's no ambiguity whether or not something happens. If you are hit you are hit. If you get spells cast at you, that is what happens. If you are high enough level to shrug them off, that is what happens. OOC skill with weapons is recommended. Some people dislike the fact that you need to be good with the weapons in order to do well. Some people ignore this, and play with the shiny weapons and get good at it. I guess we'd need a liability waiver to do this sort of thing in the States.
__________________
Running Cthulhutech: Transcendent Metamorphosis: SALVATION
Running 4e: Xanadu
Playing C:tD: Thomas d'Auvergne, the best knight in Brittany
Cosmic Truth points: 1 and counting-without-counting
Sorry, can't offer much more than that, as I've never really gotten into the live-action thing, so I know precisely squat about how they actually hold up in play.
Like the questions says. What systems are there and if you don't mind what resolution system do they use? Thanks!
I think most of the pre-made systems I know we're already mentioned, most notably Dynamic Nobilis, MET and Passion Play. Like some others, I'd love to try out Passion Play.
Personally, I prefer to use homebrewn systems with little or no mechanics. The only rules usually concern combat or special abilities, where a simple values (say, from scale of 1 to 5) are assigned and then compared with another character's values if needed. It's fast and it breaks the flow of the game as little as possible. It lacks the random element, though, but I still haven't bumped into a way of including the random element in a way which wouldn't be ankward.
Sometimes special abilities or items or something like that can be used so that the effect is explained to the affected characters accompanied with a pre-agreed meta-word. Like: "True: This drink includes ingreditends that make you feel dizzy ten minutes after you've done with it. It tastes just like it usually tastes".
The system isn't my own invention, but it works for me.