This spell allow the caster to choose a target within short range and share a skill they possess. This does not tell you if they have the skill or not and if you cast it on them you get their skill level even if it is lower than yours. The person you are borrowing from may not even know you are "sharing" their skill but get a save throw anyway. Anyone can willingly give the their skills. The user can not receive more levels than they could normally have for their level or a maximum of ten ranks whichever is satisfied first. So a 3 level mage attempts to nab some spellcraft from his master can only get a total of 9 ranks (what he would be able to have naturally).