Next in the Thief Skills As Surprise series (list of links below) is something that at first thought seems to have nothing to do with surprise: manipulating small mechanical devices like locks and traps. But if you think about it, one of the goals of picking a lock is to open a door without having to break it down, alerting everyone to your presence. It’s basically an attempt to preserve the element of surprise. And traps, in essence, surprise their victims. Avoiding a trap is a matter of reaction time: the faster you can pull your hand away, the less likely you are to be jabbed by a poison needle.
So, even if it may seem a stretch in some cases, treating Open Locks and Remove Traps as surprise rolls isn’t too bad a choice.
Both are technical skills. The average person cannot pick a lock or remove a trap without training. They can try brute force, smashing a lock or an apparent trap on a chest, but this negates surprise and makes the device unusable.
A person trained in the appropriate skill (lockpicking or trap tinkering) can open or disable mundane locks and traps, as long as they have the appropriate skills. The character is effectively Level 0. Most locks and devices are Level 1, although a simple latch on the other side of a door might be effectively Level 0. Unique traps and locks in a dungeon have the same level as the dungeon level they are found on. You can either use the Surprise Table or apply a penalty to the roll equal to half the level of the lock or trap.
A thief, of course, is better at both lockpicking and trap removal. In addition, thieves can open magical locks. The rules never say how this is done, which may explain why many GMs and players forget about this ability. I’m thinking: thieves are a superstitious lot, and have lots of little cantrips, gestures, and signs they use, hoping to gain some luck… and sometimes, somehow, some of them work. They can get through a Wizard Lock, with luck, although they have to match levels against the spell’s level. They can’t get through a Hold Portal spell, because that doesn’t affect the lock. It’s the magical equivalent of someone pushing against the other side of the door.
A thief can also attempt to pick a lock or remove a trap using makeshift tools. When not using actual lock picks and tweezers, a thief is effectively Level 0, but even that is better than a trained mundane locksmith, who can’t open locks without their tools.
Thief Skills As Surprise Series: