After choosing a team (e.g., the red team or the blue team) and before respawning, players must pick a "class." Each class has its own unique strengths and weaknesses, which are offset by other classes. The interdependence between the various classes represents the foundation of TFC. For example, the Scout is the fastest class in the game, but has weak armor and weaponry. The Heavy Weapons Guy (HWGuy) has deadly firepower and massive armor, but is the slowest class. Despite his heavy armor, an unsuspecting HWGuy can be quickly killed with a backstab from a disguised enemy Spy, but a Scout can remove the Spy's disguise, and the HWGuy can provide very effective support fire for a Scout trying to escape with the other team's flag. As such, TFC's class-based structure creates a Rock, Paper, Scissors dynamic wherein each of the classes offer important counters to each other. Some character types: Sniper: Armed with the deadly sniper rifle, this class employs one of TFC's rare "instant kill" weapons (the only other three being the Spy's knife, the Demoman's detpack, and the Engineer's dispenser) and the game's most powerful ranged weapon. Equipped with a scope, this weapon is extremely accurate due to its ability to zoom and strike opponents instantaneously. As potent as the sniper rifle is in the hands of an experienced player, it has its drawbacks. Specifically, a slow "charge-up" time (it takes about 3-4 seconds of holding the fire button down for the shot to kill through light armor, and 7 seconds for maximum impact) and the "tunnel vision" vulnerability while zoomed in, which greatly reduces the player's peripheral vision and awareness. This is exacerbated further if the shooter is set ablaze by the Pyro's weaponry, or concussed, rendering an accurate shot nearly impossible. Furthermore, the sniper gun has a visible laser sight which can give away the Sniper's position if he is not careful. (Note that the sniper rifle cannot be fired while running, in the air, or underwater—unless the player finds a surface under the water.) This class works best from concealment; with only average armor, health, speed, and with weapons unsuitable for sustained firefights, an exposed Sniper rarely lasts long. The sniper rifle has an "autorifle" mode that combines the weapon's accuracy with a rapid rate of fire, but this mode quickly exhausts the limited rifle ammunition. His other weapons consist of the crowbar, nailgun, and fragmentation grenades (up to 4). His "special skill" activates the sniper rifle's scope. TFC maps often feature prominent and easy-to-find battlements whose occupants are highly exposed, thus compromising the Sniper's best defense: stealth. Nevertheless, most Snipers have no choice but to use these locations, making them easily located and targeted by the opposing team. The amount of Snipers allowed on a given server is often limited for a number of reasons, but mainly because this class can be so deadly by itself, it doesn't lend itself to using teamwork. "Sniper wars" tend to develop, which can detract the game objectives for other classes. Snipers also have the ability to launch teammates into otherwise inaccessible areas by charging up and shooting their rifle while a teammate jumps on top of them. If the shot is charged sufficiently, the teammate can be launched extremely high and far. HWGuy: Often referred to as the tank of TFC (or sometimes the less endearing "fatty"), the Heavy Weapons Guy is extremely slow, but well armored, and very deadly. While firing his fearsome Minigun (or Assault Cannon/AC), the HWGuy moves even slower, but is able to cut down even the most heavily armored classes in seconds. The AC's devastating damage output is countered by notable drawbacks: it takes a few seconds of "windup" before it begins firing (allowing fast-moving classes to slip past), it consumes ammunition at an alarming rate, and it is very inaccurate when used at longer ranges. His slow speed and his inaccurate weapon make the HWGuy a sitting duck out in the open. Furthermore, skilled players are often able to circle-strafe inexperienced HWGuys to death. Larger maps limit the effectiveness of the slow-footed HWGuy, but this class is a force to be reckoned with when holding down a defensive choke point, or providing cover in an offensive support capacity. The HWGuy also spawns with the crowbar, single and double-barreled shotguns, 2 MIRV grenades, and up to 4 normal grenades. Due to the simple "point and kill" nature of his weapons and his high survivability, this is an excellent introductory class for new players to learn the game's basics. Spy: The stealth assassin of TFC, the Spy has fairly light armor and average speed, but has the unique ability to disguise himself as a member of an opposing team. His "special skill" button brings up the disguise menu, letting the player choose what team and what class he would like to appear to be. Enemy sentry guns will not fire on a Spy disguised as a member of that team, making them very capable of penetrating a base's defense. A disguised Spy can also position himself behind an unwary enemy to deliver an instant-kill stab (in the back of the head) with his knife. Attacking with the knife or firing any weapon causes the Spy to lose his disguise, but tossing grenades does not, making Spies ultimate sentry gun killers. The Spy can also feign death, letting him bide his time as a corpse while he changes disguise or plans his next move. Geared more for offensive support, the Spy is one of the most challenging classes to play effectively, but a skilled Spy can be very disruptive against the enemy team. Even suspicion of a Spy in the enemy team's midst can create a gaping hole in an organized defense, as defenders waste ammunition shooting each other for "Spy checks" (enemy Spies still visibly bleed if damaged) or are lured out of position. It should be noted that in friendly fire-enabled servers that this technique is generally thrown out of the window due to all players bleeding from being shot. However, many servers have friendly fire disabled. The Spy class lacks the speed, armor, and weaponry to hold in a straight-up shootout against most other classes, and any contact with an opposing team's Scout or Spy will cause him to lose his disguise. Another potent weapon available only to this class is the gas grenade (sometimes referred to as a "pill" due to its shape and colors), which has a temporary hallucinatory effect, causing enemies to see and hear phantom explosions, shots, flames and tossed grenades for a short period of time. This relatively harmless effect masks the fairly moderate damage over time the grenade causes while an enemy is in its area of effect. In large doses, the Spy' gas grenades can cause severe damage. Rounding out the Spy's unique arsenal is the tranquilizer pistol, which fires a special dart that does negligible damage, but greatly reduces its target's rate of movement temporarily. It's best used on faster classes to facilitate a lethal knife strike. The Spy is also armed with the double-barreled shotgun, nail gun, and up to 4 normal grenades.