The dafult is 5.I persoanlly play at 10 because I am highly competitive. Playing the stock campaigns and missions at level 10 is not too difficult.But playing Kyth's campaigns at level 10 is a real challenge which i always relished.Rather than playing the stock campaign to make your teeth try the Combat Episodes, ity's sseeries of 7 or missions all set in 1943-44 featuring heavies like the JS-2, KV-85,the Tiger I and II, the Ferdinand.They are much better and interesting than the vanilla missions.Then you can tackle Kyth's campaigns with the Panzer III or Panzer 38(t), Rends' Barbarossa or Lockie's mission packs for variety....