Task Force
A Task Force is a large-scale story arc in City of Heroes. Task forces are equivalent to Strike Forces in City of Villains.
Task forces are similar to Story Arcs in that they are a set of missions that tell a story. Task forces are started by talking to a task force contact, which is typically a signature hero. Unlike story arcs, task force contacts cannot be outleveled, because teammates are automatically exemplared down. Task forces can be started at any time, provided a team meets the task force's requirements, and characters may run them more than once.
Restrictions
Each task force has a minimum level requirement and a minimum team size requirement that must be met before the task force can be started. Each task force also has a maximum level associated with it; team members who exceed the maximum will automatically exemplar. The task force's missions will spawn mobs at the task force's maximum level, regardless of the team's composition.
While running a task force, none of the team's other missions are available to them, and normal contacts won't interact with the player. This means that most stores are unavailable; however, Arena stores, Pocket D, and Wentworth's are still accessible to purchase (often much needed) inspirations. Once the task force has formed, you must continue to run the task force until you finish it or drop from it. Task force missions can be run over several play sessions; the game allows you to log out without dropping from the task force.
Task Forces by Level
Rewards
Task forces typically have badges associated with them and often have unique mobs.
Unlike Story Arcs, every team member receives a completion reward at the end of a Task Force, not just the leader. Major task forces (i.e. not Ouroboros) offer the option for a Pool C Recipe drop instead of the usual origin-appropriate enhancement.
Many players believe that the leader's Notoriety setting in the final mission affects the completion reward, but this is an urban legend.