Hello,
Lately we are using Stealth a lot, and we are having troubles with several things. One of them is this: how come that improved cover gives a +10 to stealth checks and total cover doesn't give anything? One of the players suggested to give a +20 as per invisible modifier. What do you think?
Also: am I correct to assume that when you move into total cover or total concealmente, you can roll a stealth check even if you were observed, since line of sight is broken? Provided you are not facing enemies with darkvision for the total concealment case...
Partial Cover
If a creature has cover, but more than half the creature is visible, its cover bonus is reduced to a +2 to AC and a +1 bonus on Reflex saving throws. This partial cover is subject to the GM's discretion.Total Cover
If you don't have line of effect to your target (that is, you cannot draw any line from your square to your target's square without crossing a solid barrier), he is considered to have total cover from you. You can't make an attack against a target that has total cover.Improved Cover
In some cases, such as attacking a target hiding behind an arrowslit, cover may provide a greater bonus to AC and Reflex saves. In such situations, the normal cover bonuses to AC and Reflex saves can be doubled (to +8 and +4, respectively). A creature with this improved cover effectively gains improved evasion against any attack to which the Reflex save bonus applies. Furthermore, improved cover provides a +10 bonus on Stealth checks.Improved cover only applies if your enemy still has line-of-effect to you.
However, look at the perception rules, under perception modifiers:
Perception though a door increases the DC by +5.
Perception though a wall increases the DC by +10 per foot of thickness.If you have total cover on the other side of a stone wall 2' thick; the perception DC for the enemy to notice you is: your stealth check +20.
Ugh, I didn't check the Perception skill, thank you!