The Demoman is one of the more complex classes available. With no weapons (outside of his melee weapon, the Scrumpy bottle) suitable for close-quarters combat, the Demoman excels at indirect combat. Armed with a Grenade launcher and Sticky bombs, the Demoman is capable of taking out enemies using clever tricks with the game’s physics engine.
The Grenade launcher is very powerful, capable of taking out classes with smaller health-pools (Scouts, Medics, Spies and Engineers) in one or two grenades. The Grenade launcher is perfect for taking out Sentry guns that are around tight corners. Sticky bombs are the perfect tool for defending Intelligence or Control points. Fire a few in some hard -to-see spots, and wait for some prey.
Despite multiple nerfs to the Demoman’s weapons through patches, the TF2 community generally agrees that the class remains overpowered at the higher levels of play, due to the stickybomb launcher’s unparalleled versatility as a hard counter to enemy buildings, a means of setting deadly traps, and a powerful mid-range combat weapon to rival the soldier’s Rocket launcher. Ironically, Valve’s statistics page reveals that despite the Demoman’s high average kills-per-hour and decent survival rate, it is among the lower-scoring classes.