Hacker
A hacker, in terms of the JA and JO community, is a player who uses a third party program, or an exploit in the in-game engine to his/her advantage, which in turn gives the player a considerable edge against the majority of players. Hackers can also be classified as anyone who uses a third party program or an exploit in the in-game engine to disrupt game traffic, either by causing forced disconnection or server crashes.
Specific types of Hacks
One of the most common hacks used by players are scripts, these scripts are easy to create and easy to use. These scripts can be made to do certain actions when executed, the common one being auto short hops and auto rolling/force. Most servers do not provide a patch to stop these scripts from executing.
Another common form of hack tools are third party programs, usually created through C++. These tools usually require an injection of a certain exploit into the Q3 engine, which allows for the program to operate in-game. These include auto-aim programs such as Dark Side Tools, and countless ESP hacks (hacks that display certain information such as health and shield info on the users HUD).
Many hacks are usually in-game exploits that were not patched since the 1.01 update. The common ones are skin exploits and chat exploits. Skin exploits use a combination of 2 skins and the use of 2 scripts: A lag script and a bypass script. When the user exploits these scripts while using the corrupt skin, any player that is close to, or facing the player will experience an error in the skin reading system and subsequently crash as a result. Skin exploits involve accessing the engines chat system to force it to send a text command to the server, usually the command is masked so that it seems that another player is saying something that they are in fact, not saying anything. Commonly, this exploit is detected if regular chat overlaps the false chat, creating a clustered chat mix. Others include RCON blockers, which blocks legitimate Rcon commands by sending a mass volley of false ones and Fake Player Denial of Services, which sends false players to a server to overload it.
Another form of hacking, and one that poses a more dangerous threat to servers are DDoS attacks, which basically sends a large degree of false clients to a targeted server, this in turn overloads the sever and thus crashes it. This form of attack however, is the most easiest out of any other hack in JKA and JKO. For the most part, protection against these attacks are also easy to acquire, for many server providers have built in security which protects servers from third party attacks. Another form of DDoS is the getinfo exploit, which causes a buffer overload in the server. However, this again is easy to bypass.