The Slayer Chronicles
This was partly inspired by Gabe's "It Takes a Town" idea. Just to give credit where credit is due.
This is the Story of a Dwarf. Not just any dwarf, but the Legendary Slayer Gungnir, who with his Noble Companions saved more towns and put to rest more monsters than I can recount in an evening's storytelling. But tonight, let us go back, all the way back to Gugnir's beginning, when he was naught but a disgraced dwarf, shamed into taking the slayer's vow through a great wrong done to him. How did a simple dwarf become a legend? Gather round, my friends, pour me some mead, and I shall tell you the tale...
The Premise: An NPC/Nate begins the game as a Dwarf Troll Slayer. Whether characters want to roll stats and assign (apparently the mostest grimnest method) or divy out points, is up to the players as a collective. All other characters can be whatever classes the players want. Everyone other than the Slayer (no more than one slayer, btw) has been saved by/vowed to protect/is loyal to the death to the Slayer. While the slayer is hell bent on dying in combat against a worthy foe, everyone else is determined to keep him alive: as such they are forced to accompany him on his insane treks.
Gameplay: The game runs as a series of "mini-campaigns", lasting 2-3 sessions, I expect. Each mini-campaign begins when the Slayer, after much fruitless searching, gets wind of some monster he is sure is worthy enough/powerful enough to take his life honorably (beginning with a Troll, followed by a Giant, followed by...look it up). This means there would be 3 mini campaigns, with the possibility of a fourth if people enjoyed it enough (I would create a 4th slayer class for this, with the 3rd class likely being replaced by a "dragon slayer" and the fourth beign "demon slayer", more on this below). The characters can plan, plot, and prepare however they want. The mini campaign ends when the monster is dead.
Each game session gives 100 xp. HOWEVER, as soon as the monster of the given mini campaign is dead, every character immediately advances to the next career, gaining all the advances/required gear. Between each mini-campaign, presumably several months passes (giant threats like that aren't everywhere...). Also, each campaign comes with a "reward" from a town/county/whatever of 1D10x100 GP that the characters can divy up to buy equipment. Characters may do extra missions if the reward for a given monster is insufficient for their tastes or if they just want more lootz to fight a given enemy (lower level enemies for these, of course).
If the slayer dies, the game (as in, the entire game) is over. Whether or not he gets fate points, I don't know yet. The campaigns continue until this happens, with bigger and badder enemies, or until the players get bored.