Whitebox House Rules Part 5: Thieves

I wasn't even sure if I should add this class, I'm still not sure... since I'm allowing fighters to specialize I thought about keeping all the rules behind this class a secret to my players and have a specialized fighter "kit" called the "second story man" or the "bandit" or the "thief".  I was thinking that they could choose to wear light armor, focus on stealth over brawn, without the skill list to go with it.  If I do decide to use an actual Thief class, this is how I would do it:

Thief: humans/half-elves (10^th), halflings (8^th), dwarf (6^th)

Exp, hit dice, and combat abilities as cleric.  Dex of 15 or higher = +5% exp.  Dwarves and halflings suffer a -10% experience penalty (which can be partially off set by high dexterity).

Thieves only wear leather armor or lighter and use light weapons and short bows, and light x-bows.  +1 to saving throws vs. traps.

Back Stab:  if a thief sneaks up on an opponent, they get the normal attack bonus  against an unaware opponent.  If they hit, they gain x2 damage.  At 5^th level they get x3 damage and at 8^th level x4 damage.

Challenge Resolution System:  handled by rolling 1d6, roll of 6 always fails, all characters (fighters, elves, dwarves, etc… can perform these, but thieves get a better chance)

Skill	Normal Class Skill	Thief Starting Skill
Find Traps (secret doors)	2/6	3/6
Remove Traps	2/6	3/6
Move Silently/Sneak	2/6	3/6
Hide in Shadows	2/6	3/6
Open Locks	None	2/6
Hear Noise	1/6	2/6
Climb Walls	NA (use equipment)	Special
Pick Pockets	1/6	2/6

Dwarves automatically get 4/6 chance at finding/removing underground traps.

Elves automatically get 4/6 chance at noticing secret doors.

Halflings automatically get a 4/6 chance at sneak, and hide in shadows.

At each level a thief can improve one skill by a single rank.  The same skill cannot be increased two times in a row.

*The Core concept of using all d6's to resolve thief skills is a combination of earlier posts of mine, here, and here, combined with the "Delver's Delve" article by David Bowman p3 of Fight On Winter issue 2009.  The "normal" class skill is a suggestion of how to resolve the action but I'm planning to think about this.  I've always appreciated the theory behind not having a thief class.  Since none of my players have decided to play a thief yet... I'm keeping this one fluid, and will rely on situational rulings not rules for now...