Stealth & Surprise

[nittanytbone14]

I would appreciate a bit of commentary on the mechanics for stealth & surprise.

For example, if a band of orcs is hiding in ambush, do they attempt a Hide (DEX) check? Or do the PCs attempt a Spot/Listen (WIS) check?

If a PC is attempting to sneak past a guard, do they make a stealth check fo some sort, or does the guard make a perception check of some sort? Or is the guard entitled to a perception check if the stealth check succeeds?

I see a few ways to resolve it:

BTB - Use WIS to spot an ambush per PHB 115. This means that the ambushers are automatically assumed to have gained concealment. The only factors that are variable are (A) the WIS modifier of the ambushees (including if WIS is prime) and (B) the HD or level of the ambushers. Thus, an 8th level rogue in hiding has the same odds to ambush a given foe as a hill giant does, unless the CK rules that the giant may not add its HD to hiding checks.

PCs always Roll - The PCs make stealth checks when hiding (Hide / Move Silently) vs. the HD of the foe. The PCs also make perception checks (Listen) vs. the HD of the foe to spot a hiding enemy. Monsters never roll checks of their own.

Thank you for your attention. The odds of success for stealth vary significantly depending on which method is used.

[serleran]

Quote:
For example, if a band of orcs is hiding in ambush, do they attempt a Hide (DEX) check?

Only if the CK determines they should not have a reasonable chance of success, and therefore a roll is needed. The SIEGE Engine works both ways... if a character would not need to roll, a monster would not, either. Basic answer, though: yes, but under ideal circumstances (ie, the monster is ahead of the party by a few miles, knows the terrain, is intelligent and capable of ambushing...) no.

Quote:
Or do the PCs attempt a Spot/Listen (WIS) check?

Unless the CK determines the situation does not warrant it, due to 1) complete inability to fail (ie, the orc is plainly visible) or 2) there is no chance of detection (ie, the orc is intangible, invisible, and in absolute silence), then yes.

There are alternate rules interpretations, but the intent has always been to put the "whens" on the CK, as these situations are entirely situational. What may work in one instance may make no sense in another. Detecting ambushes and the like has always been intended to put the emphasis on the player, and their active attempt - it is not generally assumed one gets an automatic chance, but this, again, is not universally logical, so CKs are encouraged to do what is appropriate for the specific situation.

[Fiffergrund]

I agree with Serleran, but have a few points to add that might help.

The way I look at it, the SIEGE engine is active, not passive. The original intent was not to have opposing rolls, though some people use them. As a rule of thumb, the individual acting is the individual that makes the check, and a tie goes to the PCs.

Rogue is sneaking, guard is watching = Rogue makes the check vs. HD of guard.

Orc is hiding, PCs are looking = Orc makes the check (there is no spot/listen/search, remember...)

PC is hiding, Orc is looking = PC makes the check

In the event that two actions are active, say, trying to hold a door shut while the other side is trying to push it open, then that's a tie and the PC should roll. If both are PCs, then the CK will have to use judgment. My inclination would be to make the PC who is doing the forcing make the check.
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Sir Fiffergrund, Lord Marshal of the Castle and Crusade Society.

He Who Hides Behind The Elephant's Back