public OnFilterScriptInit()
{
    SetTimer("Change", 3000, true);
}

forward Change();
public Change()
{
    switch(random(3)) //Change based on the random function. If the "random" number is the same as last time it won't change.
    {
        case 0:
        {
            SendRconCommand("hostname MyNewHostname");
            SendRconCommand("mapname MyNewMapName");
            SetGameModeText("MyNewGameModeText");
        }
        case 1:
        {
            SendRconCommand("hostname MyOtherNewHostname");
            SendRconCommand("mapname MyOtherNewMapName");
            SetGameModeText("MyOtherNewGameModeText");
        }
        case 2:
        {
            SendRconCommand("hostname MyOtherOtherNewHostname");
            SendRconCommand("mapname MyOtherOtherNewMapName");
            SetGameModeText("MyOtherOtherNewGameModeText");
        }
        case 2:
        {
            SendRconCommand("hostname MyOtherOtherOtherNewHostname");
            SendRconCommand("mapname MyOtherOtherOtherNewMapName");
            SetGameModeText("MyOtherOtherOtherNewGameModeText");
        }
    }
}