Running an Ambush: Elegant solution?

[Nerbert]

I have been beating my head against the RAW stealth/perception/surprise round rules and its been driving me crazy.

I want to have a band of goblins ambush my party of PCs. For simplicities sake I'm going to reduce the scenario to Al the Goblin and Uncle Bob.

Al is hiding in a ditch behind some shrubs. Its plains terrain so Bob gets to make his first perception check at 880 ft away and Al gets +88 to his stealth check(??) because it says +1/10ft to DC in the perception rules even though this perception check has no DC. So, let's say Bob is a lvl 1 commoner with 10 Wis. He fails his first perception check. Let's assume that every time Bob rolls perception, the goblin also rolls stealth.

Question #1: When does he get to make his next perception check?

After every full 2x move round for the next countless rounds until he maybe spots the Goblin or gets surprised? Never? What do I tell Bob's player? This is obviously horrible.

Question #2: Is there an alternative to the above horrible solution?

A) Here is the only elegant answer I can think of. Take 10 on both parts, Bob gets surprised every time. No need to tell Bob's player, Bob just gets attacked wherever the goblin feels like doing it. Another benefit, super easy to resolve, just find whoever has the highest passive perception and he either spots the goblin or the goblins strike.

This is fine, its essentially the passive perception rule from 4e.

B) No one rolls for perception until the goblins attack. Basically, every ambush automatically succeeds. You lie in wait, you get to decide when to strike, then everyone rolls stealth/perception to figure out who's surprised. Basically your S/P roll is your initiative for the surprise round and you can't take actions against anyone above them? I guess?

Otherwise how do you decide how far apart people are when they spot each other? Its total nonsense.

I'm baffled, please help.

[Thaago]

Nerbert wrote:

I have been beating my head against the RAW stealth/perception/surprise round rules and its been driving me crazy.

I want to have a band of goblins ambush my party of PCs. For simplicities sake I'm going to reduce the scenario to Al the Goblin and Uncle Bob.

Al is hiding in a ditch behind some shrubs. Its plains terrain so Bob gets to make his first perception check at 880 ft away and Al gets +88 to his stealth check(??) because it says +1/10ft to DC in the perception rules even though this perception check has no DC. So, let's say Bob is a lvl 1 commoner with 10 Wis. He fails his first perception check. Let's assume that every time Bob rolls perception, the goblin also rolls stealth.

Question #1: When does he get to make his next perception check?

After every full 2x move round for the next countless rounds until he maybe spots the Goblin or gets surprised? Never? What do I tell Bob's player? This is obviously horrible.

Question #2: Is there an alternative to the above horrible solution?

A) Here is the only elegant answer I can think of. Take 10 on both parts, Bob gets surprised every time. No need to tell Bob's player, Bob just gets attacked wherever the goblin feels like doing it. Another benefit, super easy to resolve, just find whoever has the highest passive perception and he either spots the goblin or the goblins strike.

This is fine, its essentially the passive perception rule from 4e.

B) No one rolls for perception until the goblins attack. Basically, every ambush automatically succeeds. You lie in wait, you get to decide when to strike, then everyone rolls stealth/perception to figure out who's surprised. Basically your S/P roll is your initiative for the surprise round and you can't take actions against anyone above them? I guess?

Otherwise how do you decide how far apart people are when they spot each other? Its total nonsense.

I'm baffled, please help.

Personally, this is how I do it:

First I roll stealth for the goblin and I keep that roll until the ambush or something happens to change it.

I roll perception for the player (I don't let them do it because then they know something's up) when they have a chance to succeed. So if my goblin rolled a 20 (average goblin roll!) on his stealth check and the character has a +5 perception, they have a chance at 50 feet - 25dc (this is a fairly typical level 1 situation - the ambush range is well within short bow range). I would then give the characters a secret check every round.

Even with a much better perception check, say an impressive +11 from a half elf ranger with skill focus perception, the first check would be at 110 ft. If moving at a normal double move, the next is at 50, the next at -10 after passing. So even with a dynamite level 1 perception score, the ambush is most likely happening.

Of course the characters can move slowly and get more checks - just like normal people expecting an ambush.

Also liberally use situational modifiers. I would give an ambush where the goblin had time to scout out the area and find a good hiding spot a +2 to stealth. I would give a +4 if the goblin is totally covered in leaves and waiting for a signal from a spotter. I would give the players a +2 if they are explicitly being wary of ambush, or if it is a bright clear day with no noise. Likewise, running for dear life away from worgs and not being attentive would probably give a -2.

[Hrothdane]

I thought this thread said "Running an Ambush Elephant" for a second and got excited.

In all seriousness though, if there are going to be traps or ambushes in a session, I usually grab a few perception rolls from everyone at the beginning before we start playing. Also ask if they have any conditional modifiers to perception and take note.

[DM Livgin]

It's late, so i'll come back to defend/explain my reasoning later if necessary. This is how I run my encounters:

The goblin has a perception of -1 with an additional -2 penalty for sitting in ambush all afternoon and a +2 bonus cause he is actually looking for PCs to ambush, he rolled a 13 for a perception result of 12. The PCs are strolling along at overland speeds making no special effort to sneak, their effective stealth is 0. The goblin won by 12, so at +1/10 ft the goblin becomes aware of the PCs at 120ft away.

The goblin picked out his hiding spot after lunch and was under no pressure at the time, so he takes a 10 on stealth. He has a stealth of +10 and a situational bonus of +2 for picking a good spot in the underbrush, so he gets a stealth of 22. The two PCs are on normal watchfulness for being in goblin territory so take their perception checks with their normal +5 at lvl 1 and get 9 and 23 respectively. PC one will not spot the goblin, PC two will spot the goblin at 10ft.

So the goblin becomes aware of the PCs first at 120ft. He decides not to use the short bow and readies an action to charge the first PC to get with 30th. The next few rounds nothing happens (no more stealth/perception rolls, only one per encounter) then as the oblivious PCs get within 30ft,the readied action triggers and the goblin charges the closest.

Same idea for chance encounters in the forest, a bear is foraging and has +6 perception, it takes a 10 for a 16. The party ranger has a +15 and rolls a 11 for 26 total. The DC to see the Ranger is 0, DC to see the Large bear is -4, so the Ranger spots the oblivious bear at 300 ft.