Jazz Jackrabbit 2 Security

Jazz Jackrabbit 2 is quite simply not the most stable game out there. Attacks occasionally occur but, when they do, they are not usually as serious as some people think. This entry provides list of defenses against attacks.

Common Attacks and Ways to Defend Against Them

When people get attacked on JJ2, it’s usually because of an attack executed through a script or by a malicious program. Often, the person “attacking“ has no idea what it is the program does to bring down the server, so it’s important to know what to do to prevent yourself from being caught off guard by these attacks.

Laser Shield Crashes

These were, in the past, the most common attacks on JJ2. They consist of using the laser shield, which is not normally implemented into the game, to cause Access Violations with the laser beams fired. This can be achieved by just using cheating programs, like Jazz 2 Advantage, and simply shooting.

One way to prevent this was using WPE Filters located on Nimrod’s website (no longer available, an archived version of the page can be found at the Internet Archive), which block laser shields in online play from being fired.

Advanced Server Destruction Crashes

A program called ASD has been floating around the servers recently, and it has been used by several hackers to take down entire servers. The most common crashes will take down the entire game, and usually appear in the form of “Silent Massacre :: Sorry, please accept these AVs“. Besides this, the program can also create ghosts that, when kicked, will crash the server, as well as an F9 crash that will take down the game, providing the player list menu has been opened. The general ASD-crash freezes your Jazz2-executive so you have to kill the process in order to exit the program. The F9-crash gives you an access violation.

In the past, a good way to protect a server from ASD-attacks, although not against all crashes, would be to use WPE-filters that are provided here. A much cheaper way to avoid crashing is to host with a JJ2 version other than 1.21, 1.23, or 1.24, since ASD only supports these (most common) versions. This can be done either by using another version of JJ2 to host, or to use a version-editor, such as Connector, which is included in Project Controller 4. However, with the recent introduction of NeoAntiCrash these problems are a thing of the past.

Big Packet Crashes

Big Packet Crashes, or BPCs, have become a problem in JJ2. These crashes involve sending enlarged packets using Windows Packet Editor (WPE). When you get BPCed Jazz2 will freeze and you will need to exit the program and restart it. A packet only needs to be increased by 1 to become a a BPC.

Malicious Packet Crashes

One type of malicious packet is the Big Packet Crash. However, there are also other types of malicious packets that can be used to lag the server or cause an access violation altogether. Fortunately, most of these can already be countered with the latest version of NeoAntiCrash.

Miscellaneous Means of Defense


PeerGuardian 2, available at Phoenix Labs, is a simple way to block individual IP addresses from communicating with your computer. If you find a particular IP that is crashing your server, you can add that IP to PeerGuardian’s IP filter list, and that will block that IP.


A utility released by Monolith called NeoAntiCrash was made to protect online servers against most common forms of attack. The software is only in it’s early development stages, but it is currently available for download on J2O: NeoAntiCrash
In addition to its main objective of preventing crashes, version 1.1 also includes miscellaneous functions such as Respawn and chatlogging.


Currently, BlurredD’s JJ2+ is the most commonly used tool for defence against hackers in JJ2. It has NeoAC’s server protection built in and can easily handle all known forms of attack. Along with its anti-crash functions come dozens of other features. JJ2+ (beta) is available for download here. This is where feedback is given, too.

List Server Team

You can report crashes to the list server team, Monolith and Nimrod, and if they find that the IP you report has been causing trouble amongs several online JJ2 game servers, they can attempt to ban that IP from the list servers. This can limit the crasher’s accessability to online JJ2 game servers, but it is not a sure secure method of protecting against crashers.

Pest Eliminators

There is currently a group named “Pest Eliminators”, founded by ShadowRabbit, with an aim of helping to clear the listservers of “pests“, e.g. crashers. They have no official connection with the list server team nor any actual ability to block crashers from the listservers. The list server team therefore highly advises everyone that the list server team is contacted about crash reports instead.

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