From Team Fortress Wiki
Hacking is a term that describes the use of third-party programs in order to alter a game and gain an unfair advantage. Valve has a strict policy against hacking and will ban detected hackers with the Valve Anti-Cheat system, also known as VAC. Most hacks take one of the following forms:
- Engine hooks, which piggyback the client and report false information to the server.
- Game information interception, which record or report game data that should be hidden from the player.
- Engine exploits, which alter the game to the player's advantage.
Hackers can be reported to Valve by pressing the key in-game and sending an abuse report. Even though VAC automatically bans players over time, this notifies Valve of new hacks and all reports are read.
These hacks automate weapon aiming and firing without any input from the player. They range from crude programs which fire at colored player models to extremely sophisticated engine hooks that detect enemies' hitboxes by reading them from memory. The most sophisticated aimbots don't even fire automatically. As the player fires near an enemy, the aimbot only assists the player with a final tweak in order to score a direct hit.
Some aimbots are also capable of predicting player behaviour by aiming ahead and firing projectiles where enemies are likely to be.
These hacks allow the user to see players through walls and other obstacles. They range from engine hooks which detect player positions to altered video drivers and game files which render clear or translucent textures. The most sophisticated wallhacks help the player "preaim" or even "prefire," preparing to shoot a foe as he comes into view. Hooking the game engine isn't necessary for wall hacking. They can be implemented through the use of custom textures or "skins" which changes the color so it can be seen through walls and obstacles.
ESP stands for Extra Sensory Perception. The name is taken from a term Psychics call their "6th sense." Like the name implies, it gives the cheater an extra sense, and ranges from a RADAR-like display of where people are to drawing text/images on the screen of where the players are, to making the texture of the player's model drawn through walls and given a matt color depending on if they are behind or in front of walls.
This type of hack causes the user to create more move command packets per second, which makes the server think the client is lagging behind so, to compensate it "speeds" up the player. This does not affect things such as reloading or firing times, as these are controlled by the server. Weapons that rely on how many user command packets are sent, or "tick delta" as the SDK calls it, can be affected. These are, ÜberCharge charging time, Cloak, Bonk! Atomic Punch, and the Demoman's shield charge reload time. Weapons that rely on the server's interpretation of time are not affected.
This type of hack is generally used to make spectators sick or nauseous when spectating the cheater and were once a method of thwarting other cheater's aimbots. The cheat alters the command packet sent to the server and not the user's actual view. This makes it so the hacker doesn't see the spin, but everyone else does. As the name implies, it just makes the cheater's character spin.
These hacks alter network traffic to create latency. Sophisticated programs allow packets from the server to the client but delay or lose packets from the client to the server, allowing the hacker to experience fairly low latency gameplay while the server reports that the player is extremely laggy. These hacks are almost identical to actual network issues that clients can experience.
These hacks remove or alter gameplay elements to make the game easier to play. A minor example would be a hack that removes the screen effects for bleeding and Jarate. A major hack would remove weapon spread. These generally rely on hooking the client and removing the feature or placing a man-in-the-middle program that alters incoming and outgoing packets.
Unique to Team Fortress 2, the cheat can either determine if the current frame will generate a crit and fire, or constantly force a frame where a critical hit will occur.
Through a certain method, players on the PlayStation 3 can modify the key binds and enable console commands such as noclip, god, etc, in order to gain an advantage over other players. This is a banning offense for PlayStation Network and Xbox Live.