Game developers face security challenges when client-side software is controlled by players. If a server trusts client-provided data, such as character coordinates or inventory status, it becomes vulnerable to manipulation. This allows players to exploit game mechanics, such as teleportation or speed hacks, by sending unauthorized data packets to the server.
To mitigate these risks, developers implement authoritative servers. In this model, the client only sends intent, such as a request to move or perform an action, while the server performs the simulation and validates the outcome. This prevents players from dictating game results, although it requires complex logic to handle network latency and legitimate connection issues.
Common exploits include memory manipulation, packet interception, and logic flaws like negative number processing. For instance, if a server fails to validate that an item count cannot be negative, a player might sell a non-existent item for profit. Similarly, replay attacks can be used to claim rewards multiple times if the server lacks unique transaction identifiers.
Duplication exploits often target atomic operations. By interrupting the connection during a trade or item movement, players can force a state where an item exists in two places simultaneously. Developers address this by using unique transaction IDs and atomic database operations, though these measures can lead to server-wide rollbacks if exploits are widespread.
Wallhacks and ESP cheats rely on the server sending too much information to the client. If the server transmits the coordinates of all players regardless of visibility, the client can be modified to display them. Modern solutions, such as those used in Valorant, involve the server calculating line-of-sight and only sending data about entities that are actually visible to the player.
