Offclasses/更换职业（竞技）

本条目是基于标准竞技规则的竞技对战。
竞技相关的条目正在增长中。如有疑问，欢迎提出。

标准竞技阵容并不完全死板，玩家可以根据当前情况需要更换为更合适的职业。更改职业可以给予玩家暂时独立于组合的能力，并依靠占领控制点，摘人以及/或占据侧路等关键位置等方法帮助自己的队伍。

一般更换职业的玩家是队伍中的侦察兵，负责当游击手的士兵在一些情况下也会换职业。在标准队伍的成员中，一般是泛用性最强的职业会更换，更换职业一般是为了在最终控制点的争夺时获得只属于个别职业的优势。从目前统计数据来看，最常见的更换职业为狙击手，其次为机枪手再其次为工程师。

侦察兵

主条目： Scout (competitive)

侦察兵是泛用职业中最多变的，并且一般的泛用职业玩家很少在一场竞技游戏中只玩侦察兵。

侦察兵的优势

• Usually reaches mid quickly.
• Can quickly capture points alone and in pairs.
• Quickly and easily moves between areas and levels of elevation, allowing for quick flanking.
• Has strong deathmatch capability at close-mid range and can use mobility to survive at mid-long range, both with relatively little healing.
• Has high damage output and many options when attacking, allowing for quick surprise picks and successful chasing.

侦察兵的劣势

• Is generally ineffective at long range.
• Contributes little to spam.
• Has trouble approaching well-guarded areas when there aren't open flanks.
• Usually can't hold a small area for very long when under fire.

专精

Based on map and game status, some classes can provide unique benefits over Scout sufficient to make a class change worthwhile. Utility classes other than Scout are oftentimes chosen based on the skills and preferences of the player, as very few situations occur wherein one specialist utility is clearly a better choice than all others.

All specialist utilities have the following drawbacks:

• Usually becomes suboptimal once the situation changes.
• Cannot get to mid as fast as Scout.
• Cannot cap as fast as Scout.
• Causes the other Scout to lose his partner, giving him less survivability and flanking options.

火焰兵

主条目： Pyro (competitive)

The Pyro has a very specialized form of damage application and so is generally reserved for very specific competitive situations. His ability to ambush groups and cause them to become dispersed and uncoordinated is generally reserved for defense, especially on final points to counter enemy ÜberCharges.

火焰兵的优势

• Can provide pressure and distraction with ambush flames if in a good position.
• Can airblast people off of control points and/or high ground.
• Can use airblast to give his team an advantage in spam.
• Can reflect critical explosives back against the enemy team.

火焰兵的劣势

• Deals very little damage if enemies intercept him before he reaches close range.
• Has a poor approach when encountering enemies head-on.
• Cannot airblast projectiles as fast as enemies can fire them.

机枪手

主条目： Heavy (competitive)

A Heavy is used most commonly to defend a final capture point, especially if he has team mates that are dead or respawning. He is ideal when mobility is not a priority and the team needs firepower to hold an area.

机枪手的优势

• Can act as an emergency pocket if both soldiers are dead or out of reach.
• Is very good at taking out enemy Scouts.
• Makes an ideal defensive ÜberCharge target because his ammo type and hit points alleviate the need to reload or go for cover as the Über is ending.
• Can defend a point with little support firepower.
• Can physically stand on a point to block capture for a relatively long time.
• Can knock back rocket jumping Soldiers away from the point.

机枪手的劣势

• Is generally ineffective at long and mid range.
• Has an extremely slow travel time.
• Has a huge cost to speed if spun up, thus takes speed at the cost of effectiveness.
• Falls easily to Snipers, Spies, focused fire and critical attacks.

工程师

主条目： Engineer (competitive)

An Engineer is a common choice when a team needs to defend a point and has some time to set up. His Sentry Gun takes no extra damage from critical explosives, and has very fast reaction times, allowing it to deal with Soldiers or Scouts. His Teleporters effectively reduce respawn times, which is key on large maps. An Engineer is a common choice on Payload maps.

工程师的优势

• Has the strongest Scout area denial when his level 3 Sentry Gun is up.
• Can knock back rocket jumping Soldiers without putting himself at risk.
• Can provide health and ammo to his team in areas where pickups are rare (most final points).
• Takes no bonus damage from critical hits.

工程师的劣势

• Requires extensive preparation time.
• Can be overwhelmed by a Demoman quickly.
• Cannot deal strong damage by himself.
• Is vulnerable to Spies.

狙击手

主条目： Sniper (competitive)

A Sniper is the most common situational utility. He can be effective even if opponents are aware of him. He is an ideal choice when enemies are forced into open spaces, like most yards and the final points of maps like Granary and Yukon.

狙击手的优势

• Can provide area denial/support.
• Can contribute immediately upon gaining vision of enemies.
• Rarely has to sacrifice himself when going for picks.
• Can instantly kill most classes with a quick headshot or a charged bodyshot.

狙击手的劣势

• Suffers somewhat long transit times wherein he risks being ambushed.
• Has poor deathmatch.
• Has trouble dealing with enemies coming from multiple directions/routes.
• Is not very helpful for capturing points, especially back-caps.

间谍

主条目： Spy (competitive)

A Spy is the most helpful for breaking stalemates, particularly during a final point standstill. Of all of the classes, he is the most handicapped when expected or spotted before striking. Because of this, Spies are generally used sparingly, oftentimes to sacrifice themselves to kill the enemy Medic in areas where a Sniper can't get a clear shot. He is considered unfavorable when immediate efficacy and combat potential are high priorities.

间谍的优势

• Can get picks with little or no support.
• Can reach targets that are behind cover.
• Can take out targets even when all flank routes are guarded.
• Is good for final point back-caps.
• Can provide focused cleanup by watching enemy hit points and making use of his revolvers.
• Provides Sapper support when team mates are pushing into a Sentry nest.
• Can use the Dead Ringer for various support roles, such as absorbing critical hits or blocking chokes.

间谍的劣势

• Has poor deathmatch against opponents with high health.
• Takes a long time to set up picks that are usually far from guaranteed.
• Is very likely to die once he is spotted or gets a pick.
• Spy checking is very common, making Spy play harder.