The nice thing about running a dungeon to open your D&D campaign: gives players lots of choices while you build up the campaign setting
— Mike Mearls (@mikemearls) November 20, 2015
In a city or wilderness, meaningful choices are hard without lots of background info. Dungeons make that simple – go east or west, etc.
— Mike Mearls (@mikemearls) November 20, 2015
The key is to put NPCs to talk to into your dungeons. They can provide pointers/context to what's going on outside the dungeon.
— Mike Mearls (@mikemearls) November 20, 2015
Example: The PCs are exploring a dungeon just after a shady mercenary company began exploring it. The mercs are a potential enemy.
— Mike Mearls (@mikemearls) November 20, 2015
The PCs' interactions with the mercs are reflected in what's going on back in town. There are more mercs and their allies there.
— Mike Mearls (@mikemearls) November 20, 2015
Example 2: PCs captured a few of them, brought them to the town guard. Random die roll showed they quickly escaped. Instant rivals/enemies.
— Mike Mearls (@mikemearls) November 20, 2015