The prince needs elephants for his army. Adult male elephants are worth 300 XP, Female adults are worth 200 XP, and babies are worth 50 XP each. Double XP for 'unusual' elephants (pregnant, covered in tattoos, double tusks, magical, etc.)
 The Evil King has 9 evil counts, tyrannically ruling over the Kingdom; The COUNTS OF CHAOS. Defeat one to get a level up; at level 10 you can finally fight the King. Good luck.
 Conquistadors. Travel a tropical island archipelago and level up for each island that has been mapped out, the natives pacified, and a fort built to trade back to the glorious empire.
 Survival. Gain +1 XP per pound of monster/animal meat made into food and +25 XP per handful of edible berries and leaves picked.
 Lighthearted Wizard school adventures. You level up after each semester, if you pass exams.
 All of you were touched by a extra-dimensional being and are now lost in an otherspace. Instead of leveling up, you must collect memory gems to learn the skills, spells, and knowledge of other beings that were absorbed by the being's uncaring malevolence.
 Monster campaign. You get 100 XP per human you brutally murder. You get 10 XP for each human family scared off by your group's raids. Once you level up you can reincarnate into a monster of 1 higher HD the next time you die.
 Fantasy metropolis gang warfare. Gain +100 XP per street you take for your gang, get +50 XP per member you initiate. Get +10 XP if you spend all day tagging. Normal XP per HD for kills.
 You're monster hunters; and you hunt something specific. Vampires, werewolves, etc. Your level is HD of your biggest kill.
 Everything your character can do is based on stats. You increase stats through training, drugs, and magical elixirs. Develop super Strength for multiple attacks and cleaving blows. Get really high intelligence for psychic powers, etc.
 All progression is based on equipment. You get gear which gets better as you add in powerful gems into sockets, find better base loot, add enchantments and sword oils, and so on.
 Your players are master chefs; seeking monster meat and rare ingredients for the perfect dish. Create a new recipe and wow the critics. Your level is based on your average 'star' rating; 5 stars for the greatest chefs. If you fail over and over, your rating and strength will fall.
 Players are clan members on the wild, untamed highlands, and have a blood feud with another clan. Get +10 XP per farm animal stolen, +25 XP for each yurt burned down, and +50 XP per their cowardly “warriors” you put down.
 You are deceased paladins and have become angelic guardians of the afterlife. Every 100 years you spend defending the pearly gates from the hoards of evil souls and demons grants you a level.
 Merchant caravan guards. Get +1 XP per camel that makes it to your destination.
 Defend your dirt-farm simulator. Get +50 XP for each month's worth of food you grow. You won't grow enough for the year.
 Dark Cultists. You have to complete an evil ritual to level up, which gets harder the higher you go. Each ritual also makes the Dark One stronger.
 You get gold for XP but now it's from heists. You have to steal it from the goblin banks or the great king's treasure vaults, not from dungeons.
 Megadungeon. Each floor = 1 level up.
 Find the shards of the relic; The Sacred Crown. Each shard grants +50 XP. Snort the dust for a vision of where the next shard is.