Monster Stealth Checks

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I'm curious on how other GMs handle stealth checks for there monsters for the different mods they run.

Couple different events -

Monsters spot the Party and makes a attempt to hide themselves in a hurry.

Monsters know PC are coming so can prep their hiding spots ahead of time.

Monsters are a "Lurker", they pick a very good hiding spot and stay there till someone comes in range.

Would/should you give any bonuses to the monsters roll for stealth in any of those events?


Reason why I'm asking, is I just ran a module with a "Lurker" type monster. Had a great +Stealth skill but I rolled a 1 on his D20 stealth check and just about everyone in the party spotted him.

What I'm thinking about doing in the future, is still doing the D20 rolls. Just giving the hide checks a bonus to the roll, just haven't figured out how big yet, per situation.
I pretty much just either roll a Stealth check or take 10. Normal rules for distance, distraction, etc apply of course.
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I will generally always assume the creatures take 10 on Stealth checks, since I don't want an inordinately lucky or unlucky roll to have that much impact.  A creature rolling a 1 or 20 is great in the middle of combat, when the players can see what's going on and feel good or bad about it.  Not so much fun when it's a "Yeah, I'm not being unfair about the ambush; the creatures just rolled well" sort of situation.

If you do believe in rolling, keep in mind that you can decide to have only one creature--the one with the lowest modifier--make the roll.  (DMG, p. 36).  Otherwise, if you have 5 or 8 creatures all trying to hide, it's almost certain that at least one is going to botch it.

If you can, hide somewhere were the PCs do not have line of sight to the creatures, as that makes things a good deal tougher.  The DC is +5 if listening through a door, +10 if listening through a wall.  Arguably, creatures get a pretty hefty bonus if you don't have line of sight and they're not moving around: it's a DC 35 Perception check to hear that someone is standing on the other side of the door drawing a weapon, for example.

I do get annoyed by modules that specify ambush tactics for the creatures and then fail to properly give them any way to realistically succeed at hiding if you're playing by the rules.  If, for example, you take paragon-level creatures with no Stealth and a +9 Dex+level bonus, and specify a hiding spot where they only have normal cover vs. the PCs, please don't bother detailing how long they're going to wait until springing the ambush.  Any group that's even slightly competent (all you need is one PC who is trained in Perception or is Wis-based) is going to automatically see them from 50' away.
I preroll a stealth check for any monster that might start a battle hidden.  If the monster hears the PCs coming, or if it has a reason to be hidden, I don't want the PCs seeing me roll that die - it is a dead giveaway that there is danger afoot. 

However, I always use a die roll when a monster wants to hide.  The PCs use their passive perception against the stealth check unless they are specifically searching.  IMHO, PCs should spot hiding enemies about 33% of the time - not every stealthy monster should sneak up on the PCs.
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When in an ambush, pre-rolling is a good idea. I would not let a bad die roll stand, as it really is in everyone's interest to have a proper combat - a really bad stealth roll can ruin the role the monster should play and the 'surprise' aspect of the adventure.

In combat, anything goes. If the lurker on round 3 tries to hide and does so poorly, so be it.

I would not give a bonus to the check, as the adventure should state that if it should apply. Re-rolling a bad initial roll may seem like the same thing, but it isn't. Rather than a bonus, you are basically stating that a minimum (taking 10 is a good rule of thumb) makes sense for ambush conditions.

I am doing the same thing, roughly, with initiatives when the adventure should be challenging. I pre-roll when prepping the adventure. If the creature rolls low I consider its role in the combat and whether it really should do better to pose a decent challenge. If so, I may swap initiative with another monster (along the lines of what ADCP2-1 does), or I may re-roll and take the more appropriate of two rolls. If the result was a significant change, such as changing two out of five monster inits from what I rolled, I might make a note and prepare to "dumb down" the tactics a bit if the table is having too great a challenge - after all, it is only fair to give them a break if I gave the monsters one.

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I myself prefer to roll stealth and stick with the numbers.

In general, I would advise DMs not to hinge the ultimate effectiveness of an encounter on whether or not a certain enemy, trap, or hazard is seen or not. The gelatinous cube comes to mind. A lot of its threat is in its stealth, because it's not fast. If you want to use a gelatinous cube, it would be a good idea to couple it with allies who can help it get into range, or move the PCs close to it. Most lurkers need some cover or environment to their advantage, and everyone likes having synergy with their allies.

Other than that, I think DMs should be able to ambush the characters whenever they want to ambush them. I mean, heck, if you wanted to, you could add an extra power to each of the monsters in the ambush. Call it "Proficient Ambusher": "Free, Encounter: The (monster) is undetectable by any means prior to the start of combat. That is, it always receives a surprise round." Now, that's a bit extreme, but you could also just give them very high stealth, and something like Reactive Stealth of the gnomes, and call it good.

You don't want to utterly kick their Perception skills to the curb, but Perception has uses beyond just avoiding planned ambushes and it's not fair for a very high Perception to utterly quash all chances of an ambush. Ambushes are exciting.

[N]o difference is less easily overcome than the difference of opinion about semi-abstract questions. - L. Tolstoy

In general, I would advise DMs not to hinge the ultimate effectiveness of an encounter on whether or not a certain enemy, trap, or hazard is seen or not. The gelatinous cube comes to mind. A lot of its threat is in its stealth, because it's not fast. If you want to use a gelatinous cube, it would be a good idea to couple it with allies who can help it get into range, or move the PCs close to it. Most lurkers need some cover or environment to their advantage, and everyone likes having synergy with their allies.

Other than that, I think DMs should be able to ambush the characters whenever they want to ambush them. I mean, heck, if you wanted to, you could add an extra power to each of the monsters in the ambush. Call it "Proficient Ambusher": "Free, Encounter: The (monster) is undetectable by any means prior to the start of combat. That is, it always receives a surprise round." Now, that's a bit extreme, but you could also just give them very high stealth, and something like Reactive Stealth of the gnomes, and call it good.



Just wanted to note that this is the LFR board; as such, unless we're talking about My Realms adventures, individual DMs don't have input on encounter design, nor do they have the option to add extra powers to the monsters.
"Of course [Richard] has a knife. He always has a knife. We all have knives. It's 1183, and we're barbarians!" - Eleanor of Aquitaine, "The Lion in Winter"
Just wanted to note that this is the LFR board; as such, unless we're talking about My Realms adventures, individual DMs don't have input on encounter design, nor do they have the option to add extra powers to the monsters.

My apologies. I clicked on a link on my page without paying attention to the fact that it was posted by Alphastream (who I know usually posts to LFR threads) or where the link actually took me.

[N]o difference is less easily overcome than the difference of opinion about semi-abstract questions. - L. Tolstoy

My apologies. I clicked on a link on my page without paying attention to the fact that it was posted by Alphastream (who I know usually posts to LFR threads) or where the link actually took me.



No worries...just wanted to clarify things for the casual reader. Smile
"Of course [Richard] has a knife. He always has a knife. We all have knives. It's 1183, and we're barbarians!" - Eleanor of Aquitaine, "The Lion in Winter"