In a deathmatch(starting age=iron age)select all ur villagers and build 5 town 
centres select 2 of them and build 50 barracks now select 1 barracks and press 
the units hotkey, like this select all barracks and press hotkey one by one. Units
will be created very quick and population limit will be exceeded by 50 (depends 
upon how many barracks u have).