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nuclear chain reaction has never been funnier

a sample of the jKEX client window


No, I did not invent this game! :o(

Back in 1986 I had my first contact with computers. The "hand of fathe" touched me in form of the micro computer ROBOTRON KC 85. The most funny game I played on it was KEX (Kern EXplosion = nuclear explosion). Me and my friends spend a lot of time with this chain reaction!


No, I'm not the first to adopt this game! :o(

I found some places on the web, where others made their own incarnation of KEX. But non of them satified my expectations. Either because they just implemented only the game (Nico.Duevelmeyer) or used a specific operating system (R@zSoft).

So I'm still missing a version that has both: the fun of the game and the possibility for players to talk to each other all over the internet. I hope that this version brings happy houres to a lot of people all over the world!


As with most fascinating games the rules are very simple:

The number of players can range from 1 to 64. For a "real" game we need at least two players. The original game was designed for 7 players. This was due to a technical limitation (only 8 colors available in graphigs mode). But it's true that a number of 7 to 9 players gives most fun.

The game board has 64 fields arranged in a sqare. The fields represent nuleusses and can accumulate protons (the token within this game). In each Round each player puts one proton onto the game board. Players have an infinite number of protons available. Possible places are empty fields or fields already containing own protons.

It sounds quite stupid so far, doesn't it?

The fun came in, if the number of protons growed! Each field can only hold a certain number of protons as shown in figure 1.

figure 1, "safe" numbers of protons
1 2 2 2 2 2 2 1
2 3 3 3 3 3 3 2
2 3 3 3 3 3 3 2
2 3 3 3 3 3 3 2
2 3 3 3 3 3 3 2
2 3 3 3 3 3 3 2
2 3 3 3 3 3 3 2
1 2 2 2 2 2 2 1

If you put one more proton into a feeld, this nucleus became instable and exploded. This means the protons (including the new one) leave the actual feeld and jump into the neighbour fields as shown in figure 2. If the neighbour fields belong to other players, the protons there in became property of the current player. This can also be seen in figure 2. If the neighbour fields already contained the maximun number of protons, then another explosion occured. A chain reaction is running! Again reffer to figure 2. This way a player can take over a lot of fields by putting just one proton! Winner is the last player having protons on the field.

figure 2, how the chain reaction works.

Future Plans

This game should be playable over the internet. Therefore I choose Java vor the programming language to be independent from players favorite operating system. At the moment the client is implemented as an application but I think a browser-interface in form of an applet would be nice to have in future.

The actual version I coded with my friend Markus Dolze only implements the game itself. But I'd like the players to chat. So the new version growing with this project has two parts: the chat and the game. The player will be able to follow both: a global chat with all players on a server and a private chat room for the certain game the player is playing. Also private messages to a single Player will be possible.

The actual version manages the players colors on the server. This way two players never have the same color, but otherwise a player must be assigned to a game and cannot be "waiting" while connected to the server. But within the internet players usually don't see other players monitors. So I think color management schould be done on client side. This way the player can choose it's favorate color eaven if all other players choosed the same. Remote players will be assigned random colors. Within chat and game the local player may assign colors of his choice to remote players.


I think this can be a nice litte project for beginners (as I am :o). If you think you could like the game and want to support it, please visit the project page and let me know, what you are thinking about it!

happy coding!

Timothy Truckle
I'm a truckle but I don't like to truckle!
[Gerhardt Prokopp "Der Samenbankraub"]