Dungeons are labyrinthine constructions built around a dungeon core, often run by a blackhat guild, and used to protect the entrance to its headquarters. The presence of a dungeon concentrates magic, the more they grow, the stronger this effect gets. Concentrated magic causes objects, creatures and people within its effect radius to be more likely to gain magical attributes. Crafted objects become more likely to be high tier, people gain rarer skills, and monsters start to spawn without the aid of summoners. The constructions attract other guilds and adventurers to come and raid them, looking for power and treasure.
Public opinion on guilds is mixed. Those in the business of dealing with guilds, adventurers and magic adore them. But to normal citizens, the risk of monster breakouts, [[Guild Conflicts], and magical abnormalities is a horrid nightmare.