var list/mobs = new
// A list that's empty

mob/Login()
    mobs |= src
    // Add the mob/src to global.mobs
    ..()

mob/Logout()
    mobs -= src
    // Remove the mob/src to global.mobs
    ..()

world
    name = "Title of Gam"
    fps     = 40
    New()
        GameLogic()
        // Calls GameLogic() on world boot
        ..()
        // Magic Spook

proc/GameLogic()
    set waitfor = FALSE
    // This allows the proc to return immediately while continuing the loop.
    var mob/m
    var tick = world.tick_lag
    // Define m & tick here so you need not recreate it for each iteration
    // You can define other local variables needed at this level for the same reason
    //      The Above Text == Fa$ter c0de
    for()
        // Infinity loop ?~? spooki
        for(m in mobs)
            // Find each mob inside of global.mobs and set it to m
            m.DoSomething()
            // Call Dosomething() on m
        sleep(tick)
        // Sleep for the value of the local variable tick

mob/proc/DoSomething()
    world << "owo\..."
    // Output owo every tick, every single one of them.