You could always leave the sector and re-enter it right away, enemies will be relocated at random places on the map (that also means they can be put inside the house again however), and unfortunately, you will have to re-explore the sector from scratch.
Also, lockpicking isn't luck related. The strength on locks range from 0 to 100. 0 being a door that isn't locked, and 100 being a door that is extremely difficult to pick. When a mercenary attempts to pick a lock, the game take the mercenary's mechanic, wisdom and dexterity skills, throw them into a formula, and ends up with a number ranging from 0 to 100+, the game then substract a percentage penalty if the merc is tired, or if the locksmith kit is in less than perfect (100%) condition. Then, if the mercenary's lockpicking score is higher than the lock strength, the door will unlock. You can retry in case your first attempt at lockpicking was made when your merc was tired, or in case your locksmith kit was in less than perfect condition (you can combine multiple locksmith kits to keep them in perfect conditions, simply put a kit in your merc's left hand, then select a second kit and click on the gray item slot underneath the first locksmith kit to combine them) but otherwise attempting to pick a lock several times will not give different results.
Mercs with high health can pry open weak locks with a crowbar, the formula to pry open a lock is: (Health / 4) + (Health / 8) - Fatigue. Hurl, with his whooping 100 in Health, is the best dude to pry crates and locks open (up to 37 in lock strength). And, although I know a lot of people use and suggest to use Ice as a field mechanic early in the game, but the truth is, with his excellent health, Ice is more effective at picking locks with a crowbar than he is with a locksmith kit.
Weak sauce locks can be blown open by rifles and sufficiently powerful handguns. Anything beyond that will require explosives: Grenade for medium strength locks and bombs for high strength locks. But if you consider blowing up a door with a bomb, I advise you blow up the wall right next to the door (up, down, left or right, not diagonal) instead, that way you will not only blow the door open but you will also puncture a hole in the wall, giving you a bigger hole in the wall to shoot the bad guys inside or storm in the building. Also remember that C4 and TNT can blow holes into walls but Eagle Fearballs do not, so if all you have on your merc is an Eagle Fearball or enough material to craft one, and you intend to blow a door open with it, put it directly on the door to maximize your chance of blowing it open, don't put it on the wall.
Personally, until you can afford Magic or a merc with an equal or superior score in lockpicking, I highly advise you to carry a couple of grenade and a bundle of TNT with you at all time just in case you face a door you can't open, or just in case you face a situation where those would be handy (which happens more often than you might think.)
Also, lockpicking pro-tips:
If there are still hostiles on the map, always equip your locksmith with the best armor you have, don't be afraid to pack an Ultra Shield in addition to your treated Kevlar helmet and your treated Spectra Shield, because picking a lock open is an excellent way to get shot at point blank range by the welcoming committee, and good locksmith are hard to come by. If you worry about the lack of pockets on an Ultra Shield and worry about your ammo carrying capacity, have your locksmith carry a gun that packs more than six rounds and have him tag along with the guy that carries the wall probe and give that guy an extra round of ammo to reload the locksmith's pistol or rifle.
Also, give rocks to the guy that carries the wall probe. Rocks are good at creating distractions, when a rock lands on the ground, it create noise, and enemies will often come and investigate that noise. If you throw a couple rocks in front of a door, there is a small chance an enemy will pop outside to investigate. And even if they don't come outside to investigate, there is a high chance that they will spend their entire turn turning and walking around the room, trying to find where that noise came from, wasting precious action points in the process, meaning when you open the door, there's a good chance the enemy will not have enough action points to interrupt your turn and shoot your locksmith.
And when in doubt, just use a bomb.
Post edited January 08, 2016 by blueskirt42