Summary of findings:
- 1 point of HiS or MS is a 0.5% increase in chance to hide.
- There will always be a minimum 1% chance to fail under all circumstances.
- Penalties are percentage based. (This is explained in more detail later.)
- The ability to successfully hide = ( 2 / ( HiS + Move Silently )) * ( |100 / ( penalties - 100 )| ). (The formula may not be written elegantly and for that the writer apologizes).
- Therefore, assuming no penalties, having 100 HiS but 0 Move Silently (MS) results in a 50% success rate. Conversely, having 100 MS but 0 HiS also results in a 50% success rate. Given the additional benefits MS most likely provides, stealth points are best put toward MS before HiS.
- In order to receive no penalty to your HiS skill check, you must be in a shadow (the shadow must make your character appear darker when he walks into it or it must be night and you must be outside -- being in a shadow at night doesn't seem to provide a bonus). (All inside locations tested were all well lit and had no proper shadows.)
- Being out of a shadow during the daylight hours incurs a 50% penalty to your skill. (This is a percentage of your skill number, e.g. if you have 50 points in HiS you will have a 25% success rate. If you have 75 points in HiS you have a 37% success rate.)
- Being indoors in a lit area seems to incur a 30% penalty (it's the writer's suspicion that this is actually 1/3). If one were to locate shadows indoors this should be negated but could not be confirmed as no shadows indoors could be located for testing.
- Neutral/Friendly NPCs and party members do not hinder the ability to hide. The effects of hostile NPCs on hiding checks were not evaluated.
- Shields (any size), helmets and leather and studded leather armor do not affect hiding success rates. Elven chainmail was not evaluated.
- Night time ends as soon as the hour on the in-game clock reads "Hour 6." Night time begins when the clock reads "Hour 22." There is no easing -- it is either night or it is not.
- In order to successfully hide 99% of the time no matter the environemental conditions requires a total of 400 points into HiS or MS as the most significant penalty for hiding is attempting to hide during the day outside of the shadows which incurs a 50% penalty. Given the data, it seems as though the desired cap for MS is 255 (the max value as it's assigned only one byte) and 145 in HiS for 400 points total which should provide a 99% success rate in all environmental conditions (2 / ( 255 + 145 ) - 50% = 100%).
The following is the data used to make the aforementioned conclusions...
300 iterations with 100 HiS and 25 MS resulted in 102 failures to hide (102 / 300 = 34% failure rate).
300 iterations with 20 HiS and 100 MS resulted in 129 failures to hide ( 129 / 300 = 43% failure rate).
300 iterations with 100 HiS and 100 MS during the day out of shadows resulted in 147 failures to hide (147 / 300 = 49% failure rate).
300 iterations with 100 HiS and 100 MS during the day in the shadows resulted in 3 failures to hide ( 3 / 300 = 1% failure rate).
300 iterations with 50 HiS and 50 MS during the day out of shadows resulted in 234 failures to hide ( 234 / 300 = 78% failure rate).
300 iterations with 100 HiS and 100 MS at night out of shadows resulted in 8 failures ( 8 / 300 = 2.6% failure rate).
300 iterations with 100 HiS and 100 MS indoors in the light resulted in 89 failures ( 89 / 300 = 30% failure rate).
100 iterations with 100 HiS and 100 MS during the day in the shadows while wearing a helm resulted in 0 failures ( 0% failure rate).
100 iterations with 100 HiS and 100 MS during the day in the shadows while holding a large shield resulted in 2 failures ( 2 / 100 = 2% failure rate)
100 iterations with 100 HiS and 100 MS during the day in the shadows while wearing studded leather armor resulted in 2 failures (2 / 100 = 2% failure rate).
If one wishes to verify the findings, add information not evaluated or work with thieving skills (or cheat), the hex information for thieving skills will be provided.
Once the character file is open, the binary shows only the adjustment above and beyond what bonuses are provided inherently through class kits and stats. For instance, with 18 dexterity, a thief will start with 20 HiS. If 20 points are put into HiS when creating the character, the hex will read 14 (20 decimal) instead of 28 (40 decimal). Until this discovery, locating the proper binary to edit was difficult.
The hex columns and rows for thieving skills are as follows:
C0x8 Detect Illusion
C0x9 Set Trap
C0xB Open Locks
C0xD Find Traps
C0xE Pick Pockets
Edited by NExUS1g, 20 June 2012 - 11:27 PM.