Tavern Dungeon

Imagine every tavern had a basement floor, where you could build a tower defense/RPGMaker esque dungeon in.

Just like with leveling and money, you use money and unlocked new items for your dungeon you can buy from the merchant.

Such as add an Orc for 500g, different traps, bosses etc. Loot tables and loot reward.
Eventually you can make your dungeon super hard, and perhaps competing taverns able to check out each other’s dungeons or perhaps an element where you as the player can clear it for new reward.