doors : how lockpick open ?

i'm at level 2 , lock pick (open locks?); when i come to a door, my character says he has to lock-pick the door, i have plenty of lockpicks; do i have to be at lock-pick level 3, or what ? thanks

If your character says: "This lock is too difficult", then you do not have your lockpick skill high enough to open it.

If he says, "I need a pick or key to open this door", then you either need an exact key to open the door OR to use the spell "Open Lock".