What is LARPing? LARPing, short for Live-Action Role Playing, is a "form of role-playing game where the participants physically act out their characters' actions. The players pursue goals within a fictional setting represented by the real world while interacting with each other in character. The outcome of player actions may be mediated by game rules or determined by consensus among players. Event arrangers, called game masters, decide the setting and rules to be used and facilitate play." There are several different types of LARPing, the most common is medieval, but there is also murder mystery, Sci-Fi, fantasy, etc. LARPing.org has several more in-depth definitions here.
I too used to LARP vampire style, both general games and back in the day Camarilla global stories. Perfered general games, mostly because I lost 3 characters to the global stories (not that they died, but that they got taken because of global stories and was not allowed to play them myself.) I have never tried any D&D style LARPing nothing really happening in my area for that.