Sudden Death is a mode activated if a map's timer runs out without either team achieving their winning conditions. Sudden Death is a server-side CVAR (console variable). By default, Sudden Death is disabled.
Like normal rounds, Sudden Death still has a time limit; however, there are several restrictions designed to hasten the game's conclusion. Players do not respawn when they are killed and Engineer buildings are instantly destroyed if their owner dies. Health kits and resupply lockers are also unavailable, meaning the only sources of healing are from Medics, Dispensers, or weapons with healing effects (such as the Black Box or the Sandvich).
At the beginning of the Sudden Death period, a player may still re-select their class as long as they have not left the spawn room yet. If they leave the spawn room and then choose a new class, they die if the option "Suicide upon class change" is checked and have to wait until the next map starts to play again.
There are several other types of Sudden Death, and the type played depends on server variables:
- Single class: Every player is the same class and cannot switch.
- Melee-only: Only melee type and Invisibility watches may be used.
- Melee-only single class: Only melee type and special weapons may be used, and every player is the same class.
Unlike normal rounds, it is possible to win in one of two ways; either by completing the original objectives (capturing the Intelligence, capturing the control points, etc.) or by killing all enemy players. If neither happens before time runs out, the match ends in a stalemate.
- Before leaving the spawn room, take a moment to evaluate and possibly change your current loadout. Some weapons, like the Vita-Saw, may have no benefits in sudden death rounds.
- Stick together, especially if your team has Medics. A group of players is much more difficult to wipe out than individuals.
- Protect your Medics and Engineers, as they are your only source of health, save for a convenient Sandvich.
- Seek out and kill lone players with your teammates to slowly reduce the number of enemy players.
- Play defensively when you have no Medic support, as every lost health point cannot be earned back.
- Engineers should build Dispensers before anything else, to provide health for teammates and metal for other buildings.
- As with Standard play, try to stick together. The lack of splash damage with melee weapons means that bunching up is a good tactic, allowing for multiple hits against opponents, as long as you don't hit your teammates.
- Try to fill in as many slots as you can. Some classes, such as the Demoman and Sniper, have passive primary and secondary weapons, which can give you an advantage over the enemy.
- Regular melee tactics apply; try to feint and dodge your opponents' attacks, landing your own hits when they cannot attack back.
- Engineers cannot build Dispensers and Medics cannot heal you (unless they use the Amputator taunt), so every health point is precious. Play defensively and attempt to ambush your opponents.
- Demomen with the Chargin' Targe or Splendid Screen are very dangerous, as a guaranteed crit can easily kill many classes in one hit, especially if they are using the Scotsman's Skullcutter or Ullapool Caber.
- The Spy is particularly dangerous with his backstabs; attempt to get behind the enemy and try not to get cornered. If all else fails, going for a lucky backstab, or cloaking and running away is better than simply slashing their face.
- Sticking close to any Medics carrying the Amputator is generally a good way to stay healthy in Sudden Death, where health is very scarce. A Medic becomes defenseless upon playing their Medicating Melody, requiring protection from other players so that he is not attacked and killed.