Spy

The Spy is a suave backstabbing rogue that has the ability to insta-kill any class in the game with their knife. Spies are valued in that they can get important picks through the manipulation and deception of the enemy team. The Spy arguably has the worst direct combat ability, as it is solely designed to only get one or two kills at a time. As a pick class, the Spy will usually target the enemy Demoman, Heavy or Medic and either get the Medic to pop or drop his Übercharge. The Spy is also capable of incapacitating and destroying the Engineer's buildings.

6v6

Main Article: Spy (6v6)

In 6v6, the Spy is considered an offclass. It is most often run when one team has a disadvantage and they need to try and create an advantage (usually through dropping the enemy Medic's Über).

Highlander

Main Article: Spy (Highlander)

In Highlander, the Spy is often used to pick the enemy Medic, Heavy, Demoman, Sniper, and Engineer. Spies in Highlander must be aware that the enemy team has a full-time Pyro and is spychecking more often, leaving the Spy with less opportunities for picks.

The Spy is also the best scouting class in the game, providing invaluable information for his team. He can find how far along a Medic is to fully charging his ubercharge, where the enemy team is located, and in what direction they are moving towards in the safety provided by his watches.

Trickstabs

When spotted or confronted by an enemy, a spy is almost always put at a disadvantage, due to his low damage output. In times of need, Spies may use trickstabs to place themselves behinds the enemy. The are a multitude of ways to do so. While some are more useful/successful than others, each method can be used accordingly in different situations to get out of trouble.

PDA2

Melee

Weapon	Kill Icon	ESEA 6s legal?	UGC HL legal?	ETF2L 6s legal?	ETF2L HL legal?	Info
Stock Knife		Yes	Yes	Yes	Yes	The Knife is the most powerful weapon in the spy's arsenal. On back stab it does 6x the enemy's current health. When hitting anywhere else besides the back it does a base damage of 40 (also called butter-knifing). Spies have the capability of getting behind the enemy lines by means of cloaking and disguising, then using the knife to backstab enemies. Though the Knife is very powerful, players must not forget that they also have a gun.
Promotional Black Rose
Craft Your Eternal Reward		Yes	Yes	No	Yes	Using Your Eternal Reward removes the spies ability to disguise with the disguise kit. The spy can only disguise by successfully backstabbing an enemy. Upon backstab, the Spy will immediately disguise as the victim, the victim's body will disappear without noise, and the enemy team will receive no killfeed of their teammate dying. In the competitive scene, this knife holds controversy due to the fact that without a disguise it is near impossible to get the initial backstab.
Craft Wanga Prick
Promotional Conniver's Kunai		Yes	Yes	No	Yes	When the Conniver's Kunai is equipped, the player starts out with 60 health. On backstab, the Spy absorbs the victims health. The maximum health the Spy can reach is 180. Upon backstab flames can also be put out. The controversy behind this knife is whether or not starting out with 60 health is worth getting health later.
Craft Big Earner		Yes	Yes	No	Yes	The Big Earner grants the Spy +30% of their cloak meter upon backstab, but trades it for 25 less health. As the Spy is already a fragile class, the health debuff makes this knife one rarely seen in competitive play.
Craft Spy-Cicle		No	Yes	No	Yes	The Spy-Cicle acts like "Pyro insurance" in that, when the Spy is lit on fire, the Spy-Cicle melts and allows the Spy to become fireproof for 2 seconds. This is useful for keeping the Spy alive in order to find a better opportunity for a pick, but the Spy-Cicle is still melted and unusable for 15 seconds. As well, the Spy-Cicle is a silent killer that makes no noise on backstabs. Backstabbed victims are turned into ice sculptures, revealing the Spy's presence.

External Links

DarkNecrid's Comprehensive Pub & Competitive Spy Guide