Demoman

The Demoman's role in competitive TF2 is area denial, choke spamming, and crowd control. He is also expected to take down sentry nests. With the Stickybomb Launcher, the Demoman can do the most damage in the game, and with multiple people in a small space, he is able to do large amounts of damage. A good demoman can hold off an entire team with well-timed spam. He is the first to the midfight because of the high damage he can do and is also the class used for most often for a kritzkrieg push because of the charge ability of the stickybomb launcher, the amount of damage he can deal without having to reload and because it does the most damage with a critical hit.

Primary

The Grenade Launcher

Recommended for medium to close range. A single grenade (or "pill") can do 102 damage when it is a direct hit. It can vary between 102 and 99 depending on how close of a direct hit the pill is. It is often used to spam chokes when the demo already has a sticky trap set up, and because pills are tangible they can roll across the ground if they have not hit someone directly before touching the wall or floor or ceiling (these are often called rollers). Rollers can do 35 to 70 damage depending on the distance from the person they are near.

Booties or reskin

The Ali Baba's Wee Booties increase the demoman's health from 175 to 200, allowing him to take more spam and survive for longer. Many demomen wear the item because their grenade aim is off or bad, or for kritzkrieg pushes in order to stay alive longer without invulnerability.

Loch'n'Load

Most demomen do not use the Loch because of its required high-accuracy aim and also because of the heightened splash damage taken from a close range pill, but also because other players not hit by it do not take splash damage.

Secondary

Stickybomb Launcher

This is the most versatile weapon for the demoman, and almost all upper-level competitive demomen swear by it. It can be used for almost any range, from close to medium to far, because of its charging ability. A single stickybomb (mostly referred to as a "sticky") will do 135 damage maximum and 20 damage minimum depending on the distance of the enemy player. By holding down the left click button, you can charge a sticky in order to fire it farther for each second you charge. Many use this for area denial by spamming long-range stickies through a choke point that is too long for pills to reach. It is also used to plant a "stickytrap", a small, packed together group of stickies on a wall outside of a choke point that is detonated when a team pushes through, dealing high amounts of damage. Some well-placed stickytraps can often go unseen and may even kill multiple enemy teammates. It is also used for sticky-jumps, where the player places a sticky under their feet and detonates it to propel them in a certain direction at high-speeds. The minimum damage from a successful stickyjump a player can take is 40, and can do around 100 damage max (often resulting in a failed stickyjump.)

Charging Shields

A very small portion of high-level players still use this, as it denies them the ability to arrive at midfights first and a fraction of the damage that they could do before, and with many new updates disabling some charge scripts, many find it harder to use without a clear path.

Scottish Resistance

Grants the ability to see where all of your stickies are placed, however it also increases the prime time for stickies by almost a full second. It also does less damage.

Melee

Bottle or reskin

The stock bottle always does 65 damage and swings at a mid-range for most melee items. Most players use the bottle or other re-skins of it, often the pan or scottish handshake. Because it does more damage than most melees, players often use it when they are in a close range fight with low health and the splash damage from their weapons would kill them.

Ullapool Caber

Deals 200 damage, while also dealing 100 to you. Used for medic picks in Highlander, though it was recently banned in several leagues because it is over-powered.

Eyelander

Often used in combination with booties as the 25 health reduction is debilitating for some, the Eyelander has one of the largest melee ranges in the game. It grants an extra 15 health with each kill with it.

Persian Persuader

While the ammo to health conversion may help in some situations, it becomes impossible to use stickies to spam chokes as you quickly run out.

In Sixes

Main Article: Demoman (6v6)

In 6's, Demoman holds the primary role of dealing initial damage and crowd control. He makes sure the enemy never pushes into his team without taking damage and uses his spamming abilities to funnel the enemy team so they can be cleaned up by his teammates. He is also essential for defending as his sticky traps can net him easy kills and force the enemy to retreat, and his pill spam can easy chunk the enemy teams health if they are careless with their positioning. Demo is considered one of the harder roles in 6's due to his lack of mobility, causing him to have to consider his positioning carefully if he wishes to both not die quickly in a fight and still do substantial damage to the enemy.

In Highlander

Main Article: Demoman (Highlander)

In highlander, the Demoman's main job, is area denial. His weapons are great at dishing out high damage to numerous players at once, but fall short when it comes to accuracy. He serves a similar role as he does in 6's of damage dealing and crowd control, but he also is expected to deal with sentry nests.