look at all these numbers: skills

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in the rules cyclopedia
-only the thief has skills
-the skills are hide in shadows, move silently, climb, open locks, find traps, remove traps, pick pockets, hear noise
-the thief rolls percentile dice to determine skill checks.
-the 1st level thief has a small percentage chance (lowest is 10% for hide in shadows, find traps and remove traps, up to 30% for hear noise) to do these things, by far their best skill is climbing walls (90%).
-the 10th level thief has a reasonable chance (50% for remove traps - 70% for hear noise) to do these things, and a very good chance (95%) to climb walls.
-higher level thieves can be assigned skill check percentages that exceed 100% - the highest listed is 195% (to pick pockets, at lv36 - that same thief's worst skill is find traps, at 110%)
-the dm assigns penalties (examples given are -5%, -10%, -20%) for difficult tasks.

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in the d20 system (third edition d&d)
-to make a skill check, you roll a d20, plus your attribute modifier, plus any ranks you have in that skill.
-everybody has skills:

-int: appraise, craft, decypher script*, disable device*, forgery, knowledge*, search, spellcraft*
-dex: balance#, escape artist#, hide#, move silently#, open lock*, ride, tumble#*, use rope
-cha: bluff, diplomacy, disguise, gather information, handle animal, intimidate, perform, use magic device#
-str: climb#, jump#, swim#
-wis: heal, listen, knowledge#, spot
-con: concentration
-misc: speak language

* armor penalty applies
# trained only; cannot make skill checks unless you buy at least 1 point of the skill.

-professions are available to all characters through use of the profession, craft, knowledge and perform skills, which is nice.
-each class has a list of class skills. you can buy 1 rank (+1, which is a 5% bonus) in a class skill for 1 skill point, or +1 in a non-class skill for 2 skill points.
- every class gets a specific number of skill points per level, modified by their INT score. The character gets four times that number at first level. the number is:

2+INT cleric, fighter, paladin, wizard, sorcerer
4+INT barbarian, druid, monk
6+INT bard, ranger
8+INT rogue

-you can buy a maximum of your level +4 ranks in each skill.
-DC10 (roll 10 or higher) is used for an average skill check. unskilled characters with no att bonus succeed 55% of the time.
-DC20 is a difficult skill check. unskilled characters with no att bonus succeed only on a 20. a good lv1 rogue (ATT +5, skill +5) succeeds on a 10, 55% of the time.
-DC25 is an average lock. a good lv1 rogue (+10) opens it on a 15, 30% of the  time.
-The highest listed DC for locks is 40 (which a good lv24 rogue (+33) will open 95% of the time - failing only on a fumble roll of 1. this rogue functions as would a OD&D thief with 165% lockpicking, which is 45% better than OD&D's maximum lv36 thief - but the OD&D thief doesn't fumble, so maybe this is negligible )


                 open lock DC
             25    30    35    40
lv1  (+10) | 30% |  .  |  .  |  .
lv5  (+14) | 50% | 25% |  .  |  .
lv10 (+19) |  *  | 50% | 25% |  .
lv15 (+24) |  *  |  *  | 50% | 25%
lv20 (+29) |  *  |  *  |  *  | 50%
lv25 (+34) |  *  |  *  |  *  |  *

. opens only on a 20, 5% chance
* opens on anything but a 1, 95% chance


-rogues can buy +5 in five skills at first level, and +2 in a sixth skill. treating these as climb, hide, move silently, open lock, sleight of hand, and +2 in search, a first level rogue is potentially very similar to an OD&D thief in terms of his abilities.
-however, the rogue in this game is much worse at climbing than is the OD&D thief. a lv1 rogue (STR +2, climb +5) is only better at climbing than is a lv1 fighter (STR+5, climb+2) where his armor is lighter. in similar armor, these characters will both succeed only 40% of the time on a typical DC20 climb check. a lv10 rogue (+19) succeeds 95% of the time, as would a lv1 OD&D thief.

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in dcc rpg

-the thief has thief skills, like in OD&D: hide in shadows, sneak silently, pick pocket, climb sheer surfaces, pick lock, find trap, disable trap - and these additional skills: backstab, forge document, disguise self, read languages, handle poison. (these recast other thief features or other skills from previous games as thief skills)
- there are three different skill progressions for lawful, neutral, and chaotic thieves. each has skills they excel at (+3 at lv1, +15 at lv10) and skills they have merely trained in (+0 at lv1, +8 or +9 at lv10).


lawful: good at hiding, climbing, finding and disabling traps. not good at forging documents, disguise, reading languages, handling poison.
neutral: good at hiding, lockpicking, finding and disabling traps. not good at backstabbing, disguise, reading languages, handling poison.
chaotic: good at backstabbing, sneaking, disguise, handling poison. not good at picking pockets, disabling traps, forging documents, reading languages.


-however, every character can make skill checks, and every character is trained in whatever skills can reasonably be said to relate to their 0-level profession (everybody gets a profession) - they roll a d20 for trained checks. For untrained skills, every character uses a d10. For knowledge that might relate to their profession, but not usually, they use a d10+2. For rolls that any adult could attempt and have a reasonable chance of succeeding, every character uses a d20.
-every skill check should add an appropriate ability modifier (usually -1, +0, or +1 in DCC).
-DCC uses DC5 (60% untrained, 80% trained) for stuff that you usually wouldn’t roll for, but this time it was really important not to fail (example is walking, but over a bridge, over a chasm, with no handrail). thief skill checks, and most skill checks for difficult tasks, are usually DC10 (success 10% untrained, 55% trained, 95% with +8 or more). a difficult task for a thief is DC20 (fail if untrained, success 5% trained, 55% with +10, the best thief (lv10, trained +15, att +3) succeeds 95%).
-climbing example: usually a DC10. the best lv1 thief (+3 DEX and +3 climb) can climb a stone wall 85% of the time - not quite as good as the lv1 OD&D thief, but pretty good. an ordinary level 1 thief (+0 and +0) succeeds on climb checks 55% - much better than the best lv1 d20 rogue.

unskilled      DC
            5     10  
d10       | 60% | 10%
d10+2     | 80% | 30%
d20       | 80% | 55%

skilled                    DC
            5     10    15    20    25    30
d20+0     | 80% | 55% | 30% |  .  |  .  |  .
d20+5     |  *  | 80% | 55% | 30% |  .  |  .
d20+10    |  *  |  *  | 80% | 55% | 30% |  .
d20+15    |  *  |  *  |  *  | 80% | 55% | 30%
d20+18    |  *  |  *  |  *  |  *  | 70% | 45% 


. only on a 20. (5%)
* anything but a 1. (95%)