Cheaters are fans of computer games who find ways to bypass the rules in them. If the game is multiplayer or saves records to the server, such player behavior is considered unacceptable. And in a single-player game that works offline, these actions are quite acceptable.
Cheating in computer games dates back to the era of eight-bit computers and consoles. On consoles, cheating devices were used, placed between the cartridge and the slot for it, and making changes to the code on the go as it was read. On the IBM PC with DOS, the executable files of the games were edited by HEX editors or they used TSR programs that change the behavior of the games. While some game developers fought against cheating techniques, others, on the contrary, put secret codes in them. To simplify the passage of the game, you could press a certain sequence of keys or move the joystick. Books, magazine articles, and then websites were devoted to cheats.
Today, the techniques of cheaters have changed markedly, but some have remained the same. Using a HEX editor, you can make changes to an executable file for a modern OS, such as Linux, Mac OS or Windows. But this is not always required, because some games today are distributed according to the open source principle. In this case, you can make changes to the source code of the game, and then recompile. Players who prefer emulators of classic platforms on modern equipment use "POKE databases" that operate automatically and are updated via the Internet. Secret codes are still in use, but their developers are now placed in games noticeably less often than before.
In modern multitasking operating systems, other, previously impossible techniques have become available. Sometimes, in order to be successful in a game, you need to quickly press keys in a specific sequence. Not all users are smart enough to do this, but you can use a program that simulates this sequence after pressing just one key. Other programs monitor what is happening on the screen, analyze the image and automatically aim the weapon at the target, or, conversely, automatically shoot when the player aims the weapon at the target manually. The former are called aimbot, the latter are called targetbot. There are even bots that take on the gameplay completely for a cheater or almost completely.
A technique that does not require any knowledge of programming or additional programs is campering. The player comes to a place of the game map, from where it is difficult to see to others, and starts shooting from there. This method of cheating is ineffective: sooner or later, others will notice where he is shooting from, or read about the location on the map of places suitable for campering.
If a multiplayer game is played not over the Internet, but through a local network, and all the cars are located in the same room, you can determine where the other player is by the sound from his speakers. They fight this type of cheating by using headphones instead of speakers. Players who are poorly versed in programming may even use social engineering techniques, such as text messages (which can be exchanged in many games), provoking opponents who are good at playing but little familiar with the game's interface to press dangerous key combinations, etc.
Cheating programs can make changes to the data stream transmitted from the client application to the server on the fly. Therefore, in some modern games, data is transmitted encrypted. It is also not uncommon for the server to receive false information about the delays in the transmission of packets, while in reality they arrive much faster. During these imaginary delays, the player can perform actions, the results of which become visible to opponents only later.
Sometimes the server sends redundant information to the client application, for example, about what is happening behind the walls, but the client application does not show this to the player. Modifying the client makes it show what was normally hidden from the user. Often, the drawing of walls, like other objects on the screen, is entrusted by game developers to the graphics processing unit (GPU) located on the video card. Then not the client application of the game is modified, but the video card driver, and the walls, for example, turn out to be translucent. There are also cheating programs that allow you to see in the dark, behind your back, quickly rotate around your axis, dodging enemy ammunition, etc.
Game server owners can take pictures of what is happening on the client's screen. But he, in turn, can use a program that replaces the image with another that has nothing to do with the game. On the one hand, at the same time, evidence of the use of certain prohibited techniques disappears, and on the other, the substitution of a picture in itself becomes a prohibited technique, according to which it is immediately clear that the player is a cheater.