I found how Sneak works in UESP. Pickpocket wasn't explained there, so I looked it up and discovered what might be the correct formula
here: http://www.gamesas.com/pickpocket-succe ... 18884.html
The second comment contains it, and its source is: http://forums.bethsoft.com/topic/109721 ... /itemValue
However, I also found a thread which contradicts these, having a formula which does take the weight of items into account. Here it is: http://www.gamesas.com/pickpocketing-t14566.html
For those not interested in checking 3 websites, the first formulae:
Second formulae:Pickpocketing is a multi-stage process. Not all items in the NPC's inventory are available, depending on the initial rolls. There are checks on a steal attempt, and when the window is closed.
On initiating
for each item stack:
roll 100, stack is visible if roll <= pcSneak
On picking an item
fatigueTerm = fFatigueBase - fFatigueMult*(1 - normalisedFatigue)
where normalisedFatigue is a function of fatigue. empty fatigue bar -> 0.0, full fatigue bar -> 1.0
Note fatigueTerm is normally 1.25 at full fatigue.
checks the whole stack no matter how many you try to take
note: filled soulgems have the value of an empty soulgem due to a missing calculation
stackValue = itemValue * itemsInStack
valueTerm = 10 * fPickPocketMod * stackValue
x = (0.2 * pcAgility + 0.1 * pcLuck + pcSneak) * fatigueTerm
y = (valueTerm + npcSneak + 0.2 * npcAgilityTerm + 0.1 * npcLuckTerm) * npcFatigueTerm
t = x - y + x (yes, that's what it does)
if t < pcSneak / iPickMinChance:
roll 100, win if roll <= int(pcSneak / iPickMinChance)
else:
t = min(iPickMaxChance, t)
roll 100, win if roll <= int(t)
On closing the pickpocket window
Same calculation as taking an item, but with valueTerm = 0
Comments
The stealing process is highly broken for most items; any item or stack of items worth over 100 septims has such a negative result that it is picked at minimum chance, and this is at maximum all stats. A player with stats around 50 is picking at minimum for anything valuable. The available items window is not reset after every successful steal, only when you close the window and retry the pickpocket.
I also tried to find whether the Intelligence attribute plays a role in the cost of spells, mainly to check if playing a mage is actually viable without mods.Enter/Leave inventory:
Player.Sneak > d100 + Victim.Sneak
Take items:
Player.Security > d100 + fPickPocketMod * item Weight