Thief
 
A thief is a human who specializes in stealth, lockpicking, trap removing, and other activities. Thieves are the only characters that can open locks and find traps without using magic. As the name indicates, however, thieves do steal, though rarely from members of their own groups. Any thief who steals from friends is usually not permitted to adventure with them ever again!
In the D&D game, thieves are a normal part of life, because of their unique skills, but they are not usually welcome in the better parts of towns.
While adventuring, your thief should avoid danger whenever possible. The thief’s job is to use their Special Abilities where needed. A thief’s skills can be very useful, as they can be used over and over. For example, a magic-user may use a spell to open a lock, but the spell only works once; a thief may try to open locks whenever desired.
When an encounter occurs, your thief should stay out of the way. You may try to sneak around a monster, either to steal its treasure or to attack it from behind. You should not fight hand-to-hand unless you have to. A thief has few hit points, and although some light armor may be worn, it is not much protection.
Most thieves have high Dexterity scores. Since this can affect missile fire, you should learn the rules for missiles, and carry missile weapons. A sword or dagger will be needed in situations where you can’t avoid close combat.
Thieves are found in most groups of adventurers. The task of staying alive by sneaking and using your wits, instead of just fighting, can be an exciting game challenge.

THIEF EXPERIENCE TABLE
Level Hit Points XP
1 1d4 0  
2 2d4 1,200  
3 3d4 2,400  
4 4d4 4,800  
5 6d4 9,600  
6 6d4 20,000  
7 7d4 40,000  
8 8d4 80,000  
9 9d4 160,000  
10 9d4+2* 280,000  
11 9d4+4* 400,000  
12 9d4+6* 520,000  
13 9d4+8* 640,000  
14 9d4+10* 760,000  
*Constitution adjustments no longer apply.
THIEVES’ ABILITIES TABLE
Level Open Locks Remove Traps Pick Pockets* Move Silently Climb Walls Hide in Shadows Hear Noise**
1 15 10 20 20 87 10 1-2
2 20 15 25 25 88 15 1-2
3 25 20 30 30 89 20 1-3
4 30 25 35 35 90 25 1-3
5 35 30 40 40 91 30 1-3
6 45 40 45 45 92 35 1-3
7 55 50 55 55 93 45 1-4
8 65 60 65 65 94 55 1-4
9 75 70 75 75 95 65 1-4
10 85 80 85 85 96 75 1-4
11 95 90 95 95 97 85 1-5
12 96 95 105*** 96 98 90 1-5
13 97 97 115*** 98 99 95 1-5
14 99 99 125*** 99 99 99 1-5
*The chance of success is reduced by 5% for every level of the victim above 5th. Thus, a 7th level thief picking the pocket of a 10th level fighter would have a 30% chance of success (55 - 25 = 30).
**Roll ld6 to determine if successful.
***Once a thief reaches 12th level, the pockets of low-level characters may be picked “automatically.” However, the DM should allow a 1% minimum chance of failure, regardless of the thief’s level.

Special Abilities: Thieves know how to Open Locks, Find and Remove Traps, Climb Walls, Move Silently, Hide in Shadows, Pick Pockets, and Hear Noise. They also learn the skill of “Backstabbing.” Except for “Hear Noise,” each number is the Percentage chance that the thief is successful in using that Special Ability. Your Dungeon Master will roll d%; if the result is equal to or less than the Percentage given, the thief’s attempt is successful. “Hear Noise” is determined in a similar way, using 1d6.

OPEN LOCKS may only be tried once per lock, and only if “Thieves’ Tools” are carried. The thief may not try again with that lock until gaining another Level of Experience.

FIND TRAPS may also be tried only once per trap. If a trap is found, the thief may attempt to remove it.

REMOVE TRAPS may only be tried if a trap is found. It may be tried only once per trap.

CLIMB WALLS applies to any steep surfaces, such as sheer cliffs, walls, and so forth. The chances for success are good, but if failed, the thief slips at the halfway point and falls. The DM will roll for success only once for every 100’ climbed. If failed, the thief takes 1-6 (ld6) points of damage per 10’ fallen. Failure during a 10’ climb will inflict 1 point of damage.

MOVE SILENTLY will always seem successful to the thief. However, the DM will know (based on the Percentage roll) whether the thief’s movement is actually heard by nearby enemies, who may then take appropriate action.

HIDE IN SHADOWS means that the thief moves into and remains in shadows, also using neutral concealment. Movement is possible while hiding, but not attacking. The attempt will always seem successful to the thief, but only the DM will know for sure.

PICK POCKETS may be risky. If the DM rolls a number greater than twice the given chance for success, the thief is not only seen by those nearby, but is caught in the act by the intended victim, who may (and often does) react unfavorably.

HEAR NOISE (checked using 1d6) applies both to listening at doors and hearing the footsteps of approaching monsters. However, there is too much noise during battles to hear anything unusual.

Using thief special abilities

Watch for opportunities to use Special Abilities, and simply tell your Dungeon Master when you want your thief to use one. Be sure you understand how each one works. The attempt will automatically fail if improperly used. For Example: An ogre is charging at the party, so you say “My thief will Hide in Shadows and get out a dagger.” The DM replies, “The ogre sees the movement, and heads straight for your thief!”

Backstabbing: If a thief can sneak up on a victim, completely unnoticed, the thief may Backstab. If the intended victim sees, hears, or is otherwise warned of the thief‘s approach, a Backstab may not be taken, but the thief may still attack normally. When Backstabbing, the thief gains a bonus of +4 on the Hit Roll, and if the target is hit, the damage done is twice normal. When no battle is in progress, a Backstab attempt may require a “Move Silently” check.