Battle Start Distance

[GWJ]

Is there any formula for "distance at which one party detects the other party" for given terrain (or just dungeon)? I can't find anything

[DouglasCole]

Originally Posted by GWJ

Is there any formula for "distance at which one party detects the other party" for given terrain (or just dungeon)? I can't find anything

No, no formula. It's too situational.

If you kick in a door, you'll see the bad guys (you hope) within the room, where they're standing.

If you're wandering through a forest, you'll hear, see, or smell the other guys at some point, depending on the quality of Perception rolls. Since these rolls are penalized by distance, you can theoretically work out how far away average detection might be, but there's no easy way.

[evileeyore]

That's down to Perception/Observation rolls. I apply the range penalty from the Speed/Range table and a bonus/penalty based on SM (and any other bonuses/penalties from Ads and Disads, magic items, etc).

You roll (or let the PCs roll), Perception if they're in a hurry, Observation if they're taking their time (or Perception if it's better). If they succeed, they spot the enemy. If they fail, note the Margin of Failure. When the Speed/Range penalties decrease enough that they could have succeeded, they spot the enemy.




Personally I keep a list of the PCs Perception scores and apply Douglas Coles Rule of Passive 14... unless the PCs are being very cautious and trying to scout. Then I let them roll or Take 10 (basically passive 14 with a +4 bonus).

[EDIT]
Had to track down Doug's blogpage on it... Rule of 14 for Passive Abilities.

I should really just bookmark that page as often as I aim people at it...
[/EDIT]

[evileeyore]

I have my Players roll Perception/Observation every time they go into a new area, be that a room or new section of wilderness. Even if there is nothing of note there.

And I don't tell them the penalties or bonuses, I just ask for their Margin of Success/Failure.

[Black Leviathan]

I use the range table most of the time. So if someone is stealthing close to a fire or a noisy group and the enemy makes their contested roll by 5 to spot you then they catch sight of you about 10 yards away. If they fail to detect you then you're on top of them before they notice. If neither group is being particularly attentive then their margin of success is their Perception minus any penalties for darkness or cover.

[GWJ]

Hmmm I'm speaking more about wandering monsters, at the moment, as an alternative to the "you are seeing monster emm... 40 yard from you..." :) And especially specific penalties for (for example) forest terrain, swamp terrain, plan (+0?) terrain, etc.

[evileeyore]

Originally Posted by GWJ

Hmmm I'm speaking more about wandering monsters, at the moment, as an alternative to the "you are seeing monster emm... 40 yard from you..." :)

Well... you know the Per of the party and monsters right?

And especially specific penalties for (for example) forest terrain, swamp terrain, plan (+0?) terrain, etc.

Mmmm. My rough Per/Observation penalties:

Terrain Contours:
Flat: +5
Short Rolling Hills*: +0
Extreme Hills: -5

Vegetation Height Relative to the Searchers:
None: +5
Short "waist high" vegetation: +0
Tall vegetation: -2.5

Density:
Medium density vegetation: -2.5 (many places to hide, but still easy to move around)
High density vegetation: +0 if hiders moving, -5 if hiders stationary


* Note, if the PCs are "hugging the valleys" and not cresting hills, it's -5.
† Relative to searchers.


And this can apply to dungeon settings as well. Long, straight, empty corridors? +10.

Short, twisty, full of furniture to hide behind? -10.

Noise? If I'm being overly 'realistic' I give a bonus equal to the worst Encumbrance penalty of the 'hiders'.

[Captain Joy]

Originally Posted by GWJ

Is there any formula for "distance at which one party detects the other party" for given terrain (or just dungeon)? I can't find anything

You might find my expansion of the Stealth skill useful (or too much math to be playable).

[Black Leviathan]

If someone is specifically keeping watch you may let them substitute their tactics for perception because they're skilled at recognizing most likely approaches and finding a vantage point that maximizes visibility.

[Neveron]

Given how hearing scales slower than vision, you'll almost always hear them before you see them. This is especially true because of the way there are very few penalties to hearing but a whole lot to vision (size, light levels...)

In the dungeon, then, you can generally expect to hear the monsters from a sizeable distance (given a base-stats-only Knight/Wizard/Cleric/Thief layout, there's ~51% chance to hear someone standing still within 31yd or movement within 127yd).

Seeing monsters is trickier, especially in your stereotypical pitch-black Gygaxian dungeon. Your typical torch will only let you see out to four yards, but fortunately that party up there has a 92% chance of spotting SM+0 monsters when they get that close.
(Better lightsources mess with the odds a bit, as do brighter dungeons.)

So for the dark dungeon if you're in a hurry I'd suggest that your torch-wielding adventurers automatically hear non-sneaking monsters before they reach the torchlight and automatically see them when they're within it. The "battle start distance", then, is four-ish yards.