Sometimes it can be fun to tinker with the structure of the old school roleplaying game experience, that is commonly associated with moving around in dungeon, traversing hexes or moving through city quarters. Along the route monsters are killed for XP, treasures are gained and adventurers live and die. But, what if you do not gain any XP from exploring a dungeon. If the only thing gained in a dungeon is treasures and magical artifacts? What if you had to divide your time between exploring dungeons for loot and some other activity for XP?
Obviously, this would require that gameplay is tied to XP. If you play with milestones or solely with gold = XP, this does not mean much. However, if you play with XP for monsters or for exploring, then it does shape gameplay, or if carousing (spent gold = XP) is the main or sole source of XP, then play is sharply divided by gaining resources in the dungeon and doing XP-activity.
For instance, if XP is gained by travelling from hex to hex, by carousing in cities or from building castles or leading armies, then the dungeon would gain a different role in the game. A mega-dungeon might be a place, the adventurers return to, when they need to finance their next campaign. Or perhaps dungeons are rarer, and you need to peruse old books and travel far for your next dungeon to secure the needed ressources for your next military campaign?
Will you go, where the XP are, or where the treasure is?
How would an XP-less dungeon shape your game?