Skill Building: to upgrade troops with skill and level that skill
like Barbarian, have skill bash (little area damage) or barbar wrath (if more than 10 barbar in some range increase their attack in small amount)
archer have a chance to shoot double arrow, and upgrade skill increase their chance of double arrow
witch can upgrade Larry level by upgrade Witch skill.
some like that xD :p sorry if my English is not good... XD
