We have implemented a more aggressive anti-cheat solution to the server. This anti cheat performs client-side checks to ensure that MafiaMC is fun and fair place for everyone to play. It has come to our attention that a fairly high percentage of people feel they are above the rules and can get away with using hacked clients and their features. We have a no tolerance approach to cheating, hence this update. We didn't want to have to do this, but it's the only solution to making MafiaMC a better place. You may see the following message in chat. If this occurs, prior to running the program you will need to close down any additional instances of Minecraft that you have open. The message will appear at random for players. We will not disclose the conditions for the anti cheat to kick in, to protect the algorithm that it runs on. By completing this anti cheat check, you are helping keep MafiaMC cheat free. If you have nothing to hide, you have nothing to fear. Please see updated rules here. See changes regarding this subject below: We are working to allow more clients over the next few days, such as LabyMod, 5Zigs etc. For now, please use only vanilla or Optifine clients in order to be compliant with the above rules.