Gaming

I've been thinking about an ARPG based around World of Warcraft's mythic dungeons.

Scalable, multi-player, enhanceable instances where completion of more difficult versions of the instance rewards in better gear and crafting options.

The idea is that the content is created for a 5-man party (1 tank, 1 healer, 3 dps) but you can try solo it, or bring up to 20 people to massively increase the difficulty and the rewards. Instances would follow WoW dungeon's formula of trash mobs (which drop crafting materials and have rare drop chances for certain gear) pathing you towards a succession of bosses with very different, complex mechanics with stages, signaled abilities, and skill requirements.

This would include a character levelling system to unlock new class abilities and mechanisms, a party finder system, certain dungeons locked behind character level and the completion of other dungeons at a certain difficulty level. Perhaps you could extend it to add in "world bosses", massive 200-man bosses with a chance at particularly unique loot, but of course that would require a certain level of infrastructure and a game population making it justifiable.