Team Fortress 2/Demoman

The Demoman is a medium-to-long range class that works well in both offensive and defensive roles. They have 175 points of health and move slightly slower than a Pyro. They carry:


 * a grenade launcher (weapon 1) - this is a grenade launcher that can hold four grenades at once, and each grenade explodes after about 3 seconds (or on contact with an enemy). One direct hit will kill a Scout, Spy, or Engineer. Since this weapon isn't as direct as others, it can take a bit of skill to use this weapon well, but on the other hand pumping an area full of grenades can often work, especially in close spaces. This weapon is effective at taking out engineers and their constructions, especially if they've put themselves in a corner behind their dispensers and sentries.
 * a remote mine launcher (weapon 2) - this fires remote explosive bombs which stick to walls and some objects. The weapon itself can hold 8 mines at once and you can have 8 mines active at any one time. Pressing the right mouse button (or whatever you have secondary class function set to) will detonate the mines from any distance. Placing these somewhere you can see but the enemy can't when they pass by is a good way of catching people off-guard (especially if you place 8 together - this is pretty much instant kill on anyone). Trapping a control point so you can tell when the enemy is capturing it from any distance is also a good tactic.
 * a whiskey bottle (weapon 3) - this is the Demoman's melee weapon. After a few swings against a wall or an enemy it will smash (but damage dealt doesn't change by much, if at all).

Using Demomen
A skilled Demoman can be monumentally annoying to enemies. Although the grenade launcher isn't that well-suited for close-quarter combat unless you fire a grenade straight at someone, they can be bounced around or launched clean over obstacles to fall on an unsuspecting enemy and deal a lot of damage. The mines of a Demoman, if you can place them and time their detonation right, can take out two or three enemies in one go, especially useful for protecting an important hallway or a control point.

The Demoman has a lack of direct weapons, so is more suited for a defensive role than an offensive one unless you are competent with the grenade launcher. In which case, you should try and find some cover that you can fire grenades from towards Engineers and their sentries/dispensers, or anywhere that newly-spawned enemy players emerge from. The grenades can explode in quick succession if you don't reload in-between, and take out an Engineer and all his stuff whilst he hopelessly tries to repair them between grenade blasts.

The Demoman can also copy the Soldier and perform a grenade jump or a mine jump similar to the Soldier's rocket jump. Time it right, and at the cost of about 50 points of health you can reach places you wouldn't normally be able to get to. You might want to avoid this, because even though the Demoman is quite slow, he has 175 health and so can't take as many repeated assisted jumps whilst remaining healthy enough to fight. Also, it's harder to time and you won't be propelled as far.

Defeating Demomen
If you run into a grenade by accident or one happens to drop next to you after being fired from a distance, you are going to be hard-pushed to escape damage. Turning a corner to get a grenade to the face as a Scout or Spy can be extremely annoying, and you can die from mines placed in hidden corners inside doors and other sneaky places. Sticking to open areas where the Demoman's weapons are easier to spot and avoid is a wise move. It also helps a lot if they aren't that good at using the grenade launcher. If you've got a mined place like a control point that will explode if you try and move into it, get a Soldier or another Demoman in there - shooting, or better yet, exploding sticky mines will dislodge them and allow them to freely move around. They can still be detonated, but this way you can de-mine a place and make it safe to move into, avoiding the brunt of the damage when the owner decides to detonate them.

If you are an Engineer, try to build in places that give the Demoman no significant advantage. Unfortunately, a place that is easy for a sentry gun to defend is often somewhere that can be easily-attacked by Demomen and several other classes. Saving your own skin is often the best way out from being bombarded with grenades, since you can start building straight away using the metal you can scavenge from your constructions, rather than waiting to respawn. Ultimately, hitting the Demomen from a distance with rockets, sniping them, or getting right up-close as a Scout or Pyro are effective ways of dealing with them - since these two classes are agile enough to dodge Demoman grenades which are even more lethal when used at point-blank.