Crowds

Crowded thoroughfares and similar areas are difficult terrain, or greater difficult terrain if an area is truly packed with people. You might allow a character to get a crowd to part using Diplomacy, Intimidation, or Performance. A crowd exposed to an obvious danger, like a fire or a rampaging monster, attempts to move away from the danger as quickly as possible, but it's slowed by its own mass. A fleeing crowd typically moves at the Speed of an average member each round (usually 25 feet), potentially trampling or leaving behind slower-moving members of the crowd.