When activated, the character holds their right hand up high. This pose is held until another player taunts in front of them or they cancel it. Other players see an icon over the initiator's head indicating that the taunt is active. Any nearby player (including Bots), regardless of team or if they own the taunt, can initiate a dual animation by standing in front of the initiator and pressing their taunt key. When another player joins in, the characters go through a brief class-specific "preparation" animation, before audibly slapping their hands and celebrating the successful high five.
If the High Five! is initiated with insufficient space to perform the co-op taunt, such as a map height difference or obstacle in front of the player, the taunt cannot be initiated and a message appears on the HUD informing the player of why they are unable to taunt.
Other nearby friendly players receive a tutorial-like prompt on their screen the first time they see a player initiate a High Five informing them of how and where to accept it.
For the voice lines and animations of each class, please refer to the respective class taunts pages.
- Occasionally, a player may appear to be stuck in the right hand up position after holding the taunt between rounds. This hinders gameplay in that the hitboxes do not correspond with the model.
- The particle effect created by the High Five! where the two participants' hands collide can occasionally be seen through walls.
- If a Heavy is holding the Panic Attack and the taunt is initiated, the Panic Attack's forend can be seen in the Heavy's hand.
- The animations for the High Five! taunt existed within the game files since the WAR! Update.
- Additionally, there are some unused animations within the game files for the Horseless Headless Horsemann suggesting that high-fives originally had a chance of failing to be executed correctly at one point in the taunt's development. Two animations exist in which the Horsemann swings his arm and supposedly misses the partner's hand. The first animation consists of the Horsemann crossing his arms, bending back, and shaking his head in a disappointing manner. The second one consists of the Horsemann pointing at the partner and thrusting his middle finger upward in a rude manner. Since these animations are for the Horsemann, the Demoman could have used the same animations if these factors made it into the game, since they both share the same base animations.
- The High Five! comic "Hey Sniper!" features the Sniper who, faced with a dilemma, kicks down a chair in frustration while consulting a Mann Co. Catalogue before discovering the High Five! product. This scene is in fact a reworded copy of a panel from "The Insult That Made a 'Jarate Master' Out of Sniper", where the Sniper, angry from being picked on by men his own size, kicks down a chair in frustration before discovering Jarate from a Mann Co. Catalogue.
- Like some other things in the game, the real-world equivalent of the High Five! did not come into widespread use until several years after the game takes place.
- Using the High Five! while wearing the Barely-Melted Capacitor caused a message to appear in the chatbox during the Pyromania Update, which varied from class to class.