Pickpocket success revisited : III

» Fri May 27, 2011 11:11 pm

I have been trying to get a handle on how pickpocket works for a mod I am working on. From what I have heard and from what my owe experience reveals it mostly does not work. http://planetelderscrolls.gamespy.com/View.php?view=Mods.Detail&id=8000 attempts a fix by tweaking a game setting, but I would prefer not to impose such a change on players of my mod. Morrowind Scripting for Dummies offers a formula for both the chance of accessing an NPC's inventory and for a successful pickpocket. The latter purports that the weight of the object is significant, but my tests suggest that it is the value (in gold) not the weight that determines success.

In particular, I am trying to pickpocket keys. Keys have no weight but a typical value of 300 gold. These have been very difficult for me to steal even with a high sneak and security. When I placed several different ingredients in the target's inventory (all less than 1 unit of weight) only the low value items could be taken undetected regularly. The pearl and ruby required several attempts before they could be taken successfully. I added two new keys to the target's inventory: one with a mass of 0.1 unit (in case a key's zero weight was tripping the formula) and one with a value of 1 gold. The latter could be removed with relative ease while the more valuable key usually triggered an alarm.

It has long been a puzzle to me why keys would have such a large value and also be un-tradable. Now I wonder if their high value was to make them difficult to steal, but to compensate for this artificial value they were given no weight to make it impossible to sell (making the essentially worthless). I am pretty much settled on making my keys very low weight (more easily stolen) and low value (as they should be), but I am curious if anyone can confirm or refute my conclusions.

» Fri May 27, 2011 6:14 pm

Hi cyrano - Hrnchamd unlocked the fomulae for pickpocketing http://www.gamesas.com/index.php?/topic/1097214-gameplay-mechanics-anolysis

Unfortunately he confirms what you have trialed - I always used to get my hands burnt dipping them into pockets looking for keys too

Pickpocketing

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

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 = http://forums.bethsoft.com/index.php?/topic/1151628-pickpocket-success-revisited/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.

» Sat May 28, 2011 8:40 am

Thank you Illy. I remember seeing that thread before, but I did not look at if very closely at the time otherwise I might have remembered the breakdown for pickpocket. One can say objectively that pickpocket is very broken. There may be a couple problems with the formulas that Hrnchamd posted. I suppose that AgililtyTerm is modified in much the same way as LuckTerm however I cannot find a game setting fAgilityMod. Also in the calculation of x I expect there is a multiplier for pcSneak as there is for pcLuck otherwise it would be much easier to pick pockets than is the case.

Anyway, it is enough information to confirm my suspicions. Although I cannot make enough adjustments to make stealing keys easy I can certainly make it so a highly skilled player can be successful around half the time.

» Fri May 27, 2011 6:01 pm

and, has this been something someone (maybe Hrnchamd with his MCP) has tried to make a fix for? It sounds like it could be scripted fixed... Perhaps this will be my next project (after the trap-fix)

ST