If you don't find your particular question answered here, post in the forum! You don't need to register but can ask as Anonymous there.


I cannot start the game! What do I do?

For some people, the game crashes if they enable Triple Buffering for OpenGL in their graphics driver. Try disabling it: If you have an AMD graphics card go into the Catalyst Control Center. (You will find it by typing ccc into the start menu on Windows). Go to Games and then 3D Application Settings. Scroll all the way down and at the very bottom un-select Triple Buffering.

If this doesn't help, describe your problem in the bugtracker and post any relevant information:

  • There is a Clonk.log in your OpenClonk directory. On Windows, it's in C:\Users\[Username]\AppData\Roaming\OpenClonk\
  • What's your video card? Are your drivers up-to-date? Intel Express Chipsets reportedly have problems with OpenGL
  • Which version of this game are you using? Did you try out the latest development snapshot? Does the problem persist then?

I can not host a round on the internet! What can I do?

If you want to host a game on the internet and are behind a router, you need to forward the ports 11111-11113 (TCP & UDP) in your home router configuration. How to forward the ports completely depends on your router software, so you have to refer to your router's manual there.

For more information on ports, see Which ports does OpenClonk use?

Which ports does OpenClonk use?

OpenClonk uses the same ports as Clonk Rage. From the FAQ on clonk.de:

By default, Clonk uses port 11112 TCP and port 11113 UDP for game connections. For best speed it is recommended to forward both of these ports through your router or firewall.

For directly joining an IP address (without internet server) port 11111 TCP is required incoming on the host.

Automatic game discovery in LAN works through port 11114 UDP. If necessary, these ports can be adjusted in the options dialog. For other functions the game will connect to the internet and league server clonk.de on port 84 and port 11115 for additional hole punching.

How do I submit a patch?

This answer assumes that you are using TortoiseGit. After you checked out the source code and made your changes, you need to commit these changes. Afterwards, you can use the context menu to create a patch. This will create a new file which you can paste into a forum post. If you made or changed a binary file, please also attach it to your post.

If you use GitHub, you can also create a pull request for our project on GitHub. Be advised however that the repository on GitHub is just a mirror of our repository.

Why is this page in English? Isn't Clonk a German game?

Clonk has been a German shareware game and thus its community has been mainly German. With the switch to the English language for the OpenClonk community, we intended to widen the community to an international level and make it possible for non-Germans to contribute to and participate in OpenClonk. However, there is a German subforum now.

And of course, German, as well as other languages will continue to be supported in the game. Just the development and the community of OpenClonk will be in English.

Why did you start from scratch regarding the game content?

During shareware Clonk development, the game content stayed mainly about the same and was just extended by add-ons. This and the decision to keep the game as backward compatible as possible blocked lots of good changes and new concepts that could have been introduced in the game.

OpenClonk is a different game than the old Clonk series, it is not be just a sequel in the fashion of previous Clonk development. The aim of OpenClonk is not to replace Clonk Rage by "making it better" while keeping everything as it was before. Clonk is about mining, about production lines and economy, fast and fiddly melees, known for flexibility in scenario design and whatnot. In this project, we aim to improve these strengths, which means that during OpenClonk development more fundamental changes must be (and are) possible.

Clonk Rage on the other hand will continue to exist alongside OpenClonk as the last title of the shareware series and will continue to include all that classical and that the community has come to love. Also read this old forum discussion on this topic.

Will you convert all those great Clonk Rage expansions for OpenClonk?

No, and we never will. OpenClonk is not backwards compatible with Clonk Rage, and never will be. We have broken ties with the old game content which all these expansions rely on. Hence the name, they are expansions for Clonk Rage. Specifically, Clonk Rage. OpenClonk is a different game with different game content, graphics, and script language, and therefore cannot have it's game content expanded with expansions designed for a completely different game.

What is the license for OpenClonk?

The code is licensed under the ISC license.

The game content is licensed under mixed CC 3.0 licenses of which none is more restrictive than CC-BY-SA (CC-BY, CC 0 and CC-BY-SA). Actually, the vast majority are CC-BY, there are only one or two files that are CC-BY-SA. Nevertheless, as a whole, it can thus only be distributed under the CC-BY-SA.

See License for more information.

Am I able to play with several players on one PC?

Generally yes. However, currently this is not possible yet.

Where can I upload / download mods for OpenClonk? Are there any?

Have a look in the Player Creations board in the forum. You might also want to check the CCAN

Will there be keyboard-only controls?

No. OpenClonk is played with keyboard and mouse as the whole game is designed to utilize the advantages of mouse control. This adds a completely new set of gameplay possibilities to the game that would never have been possible in the shareware Clonk titles. However, gamepad controls are supported in the game and they work quite well considering that a gamepad doesn't have a pointing device. However you can create your own keyboard-only control scheme based on the gamepad control scheme.

Currently, gamepad controls undergo an overhaul and are not functioning properly.

Are other Clonk games available as source code?

The source code for most older Clonk versions is available from Redwolf Design. Here is a list of modified versions:

Is there an editor for OpenClonk?

Yes, the C4DT, the Clonk Development Tools for Eclipse, maintained by Mortimer. Eclipse is a powerful open source IDE that you will have heard of if you ever developed in Java. C4DT is a plugin for Eclipse that makes it possible to develop for Clonk in C4Script and even debug your code one-instruction-at-a-time using this powerful IDE.

The old explorer-like Editor.exe that you might know from Clonk Rage doesn't exist anymore in OpenClonk. However, the editor mode still exists for drawing and designing scenarios. Just start clonk with the commandline parameter --editor.

For more information on how to develop content for the game, see the C4Script Documentation.

How can I create my own game content?

If you are looking to develop your own game content for or based on OpenClonk, have a look at the C4Script Documentation, you should find everything there. See also a related FAQ answer: Is there an editor for OpenClonk?

If you are interested in getting involved and contributing to OpenClonk, this introduction on development should make you happy :-). For any other open questions regarding this, consider dropping by in our forum or in our IRC channel!

Where can I report bugs?

In the bugtracker.

How can I build OpenClonk myself?

Check out this tutorial.