How does an encounter begin?
It’s easy to fall into a simple formula: The encounter begins at line of sight (“you see an orc”) and immediately launches into an initiative check (“the orc tries to kill you”). There are usually minor variations on the line of sight (the orc opens the door, you open the door, the orc comes around the corner, etc.) and also the possibility of an ambush (you see the orc, but the orc doesn’t see you; or vice versa), but the formula remains pretty straightforward.
One way to break away from this formula is to vary the creature’s reaction to the encounter: Instead of leaping into combat, they might be friendly or attempt to negotiate or beg for help. In 5E Hexcrawl, I discuss how a mechanical reaction check can be used to prompt these disparate agendas.
I also talk about this a bit in the Art of Pacing, and also look at how shifting the bang – the moment at the beginning of a scene which forces the PCs to make one or more meaningful choices – can significantly shift the nature of the encounter:
Does the scene start when the ogre jumps out and snarls in their face? Or does it start when they’re still approaching its chamber and they can hear the crunching of bones? Or when they see a goblin strung up on a rack with its intestines hanging around its ankles… and then the deep thudding of heavy footsteps fills the corridor behind them as the ogre returns for its meal?
You can see how each of those creates a different encounter, and in most of them the scene starts before the ogre enters the PCs’ line of sight.
RANDOM ENCOUNTER DISTANCE
Another mechanical prompt that can help break the “line of sight” habit is a random encounter distance. This is a mechanic which dates back to the earliest days of D&D, but has faded away in more recent editions. But it can be a useful one in an game.
In the original 1974 edition of D&D, an encounter would begin at 2d4 x10 feet (or 1d3 x 10 feet if surprised). Many OSR retro-clones modify this to 2d6 x 10 feet.
This simple mechanic is largely all you need, neatly prompting you to think about how encounters begin in unusual and unexpected ways:
- If the distance generated is longer than line of sight, this suggests the encounter begins before the PCs can see the creatures (and vice versa), most likely because they can be heard (or their light seen around a corner).
- If the distance is closer than line of sight, what could explain the close proximity? (This is how you get moments like xenomorphs climbing through the ceiling panels.)
- In the case of wandering encounters, the result may also indicate the direction of approach: If one entrance to the room is 80 feet away and the other entrance is 20 feet away, and then you roll a random encounter distance of 20 feet… well, you can be pretty sure which entrance they’re using.
There may, of course, be times when common sense and the particular circumstances of the current situation will need to override the simplicity of this mechanic (but that’s why the GM exists in the first place).
CALCULATED ENCOUNTER DISTANCE
There’s another mechanical approach to this technique which was secretly hidden in 3rd Edition D&D.
See, in 3rd Edition there was a -1 penalty to perception-type tests per 10 feet. This meant that if you succeeded on a perception-type test, you could directly calculate the distance at which you detected the encounter by multiplying the margin of success by 10 feet.
For example, if an ogre rolled a Hide check of 15 and you rolled a Spot check of 24, then you’d have a margin of success of 9 and would detect the ogre at 90 feet. If, conversely, you rolled a Hide check of 18 and the ogre rolled a Spot check of 20, the ogre would be able to detect you at 20 feet. (Which, of course, means you would detect the ogre before the ogre detected you. The larger margin of success sets the encounter distance.)
You can follow this same basic guideline in 5th Edition D&D and many other RPGs. And, once again, if the result is farther than the current line of sight, you’ll know that the opposition must have been detected in some other way (heard them talking, spotted in a reflective surface, etc.).
WILDERNESS ENCOUNTER DISTANCES
It should be noted that both the OD&D and 3rd Edition mechanics don’t really work in the wilderness, which is why they included encounter distance tables for wilderness encounters, customizing encounter distances based on terrain type.
These tables were eliminated from the 5E core rulebooks (except, oddly, for underwater encounters), although they apparently appear on some of the official 5E Dungeon Master screens.
You can also find a continuation of these tables in Hexcrawl Tool: Spot Distances as seen here:
| Terrain | Encounter Distance |
|---|---|
| Desert | 6d6 x 20 feet |
| Desert, dunes | 6d6 x 10 feet |
| Forest (sparse) | 3d6 x 10 feet |
| Forest (medium) | 2d8 x 10 feet |
| Forest (dense) | 2d6 x 10 feet |
| Hills (gentle) | 2d6 x 10 feet |
| Hills (rugged) | 2d6 x 10 feet |
| Jungle | 2d6 x 10 feet |
| Moor | 2d8 x 10 feet |
| Mountains | 4d10 x 10 feet |
| Plains | 6d6 x 40 feet |
| Swamp | 6d6 x 10 feet |
| Tundra, frozen | 6d6 x 20 feet |
Thanks to the Alexandrites on my Discord and Twitch chat, who prompted and encouraged this tip.
What kind of terrain would you treat medieval farmland as?
I have been thinking about this very subject for some time now, especially since realizing how important establishing the point at which the PCs become aware of another creature is when setting the scene for an encounter. The random generation of encounter distance can help the DM narrow down all of the possibilities into those that make sense with the RNG result.
One thing that I’d realized is how it can (and should) reward some choices that otherwise don’t produce a mechanical benefit. RAW, in D&D 5E Passive Perception doesn’t change when searching a room, but since you put someone on lookout the monster that surprised the PCs starts the encounter much further away and has to spend that first round closing the distance. It also prevents the one PC with a high Perception from making all of the meaningful Perception checks (do I search or should I be the lookout?).
Odd fact about D&D 5E: the only place you’ll ever find official rules tables for encounter, visible, and audible distances is the inside of the Dungeon Master’s Screen.
> What kind of terrain would you treat medieval farmland as?
It seems to me that it would depend on the underlying topography, the crops being grown, the season, and the nature of the creatures being encountered. If it’s wheat, probably plains or hills. If it’s tall stalks of maize in late summer, you could hide an arbitrary number of goblins ten feet from the PCs, but an ogre will stick out a bit.
Thinking about it, this serves to emphasize both having and conveying a clear picture of the circumstances. If the GM says “You’re walking through farm land,” and the players think they’re walking over close-cropped pasture but the GM knows they’re walking through a dense orchard, the players might be less cautious than they would be if everyone were on the same page.
@Another David: The observation on searching vs. lookout is really interesting. In my Twitch stream earlier this week, we were looking at the original example of play from the 1974 edition of D&D, which includes:
CAL: The elf will check out the hollow sound, one of us will sort through the refuse, each trunk will be opened by one of us, and the remaining two (naming exactly who this is) will each guard a door, listening to get an advance warning if anything approaches.
Which later pays off:
REF: As you complete loading the dwarf at the west door detects heavy footsteps approaching.
CAL: EXCELLENT! Our Magic-User will cast a HOLD PORTAL on the west door while the elf opens the secret one. We will then all beat a hasty retreat down the stairs to the south. Onward, friends, to more and bigger loot!
I would argue – while readily admitting that Gygax and others often played more by the seat of their pants than they rules they wrote – that the original design intent as published in 1974 was that surprise be rolled first, and then, when neither side is surprised, encounter distance. This means that DM’s should be rolling surprise rolls when PC’s are within 80 feet of any potential encounter. If surprise occurs then the groups will be within 1d3 x 10 feet at “encounter” (awareness) if no surprise then they will be within 2d4 x 10. I run it this way and it works really well, allowing some interesting ambush situations like goblins bursting out of a door instead of always passively sitting in a room until the party knocks.
Yesterday we where playing 5E, the players run into a band of Hill Giants (I was using some wilderness tables, and the players went out of their way to find them). The camp had some trained Dire Wolfs around the camp, so when one of Wolfs got scared it howl and the giants from the camp went to see what happened.
I discribe that they felt the ground trembling under them, then they saw them at a distance, then I put them on a map next to them… this kind of annoyed one of the players (he is playing a Warlock that can attack with a bow at crazy distances).
I didn’t put the band straight next to them (maybe 40-60 ft. away), and the players attacked first (2 agains 6 Hill Giants and 6 Dire Wolfs… pretty stupid). So, they didn’t even try to escape at that point…
They tried to fly away, but they got hit by some rocks, two crits… even when I only use the average damage of the dice the caster got KO, fly spell ended and they went straight to the ground…
I like the idea of basing encounter distance off the margin of success of your Perception check. There are plenty of situations where, logically, one party would detect the other at a greater distance, even if neither of them is particularly trying to be stealthy. (The drow spots your torchlight from the far side of the dark cavern. You hear and feel the dinosaur’s thunderous footfalls from a mile away.) That raises the question, though: if they *aren’t* trying to be stealthy, how would you set the DC of the Perception check?
Shouldn’t rugged hills and gentle hills have a different encounter distance?
Also, I’ve never been to the tundra, but the pictures I’ve seen of it mostly look pretty flat. (Unless you’re talking about “alpine” tundra, but that’s a different matter.) Really, the only thing that distinguishes it from plains is the temperature.
In fact, I’m not sure if using categories like “desert” and “moor” is the best approach in determining encounter distance. They make for a convenient descriptive shorthand, but as sptrashcan pointed out with the example of farmland, they can also be misleading. After all, “desert” can be rugged like the Grand Canyon National Park or flat like the Australian Outback.
Instead, I’d be tempted to pick a baseline figure for encounter distance and then modify it by terrain (flat, gentle, or rugged) and tree cover (none, sparse, medium, or dense). It doesn’t have to be complicated: all you’d need is a single table that you step up or down according to the circumstances. Or if you want to get fancy, perhaps one factor determines the die roll and the other determines the multiplier. (I was going to suggest lighting and weather conditions as modifiers too, but then I recollected that in 5e, those are handled by disadvantage on the Perception roll.)
I’d also note that while hills and trees (and fog and darkness) may block line of sight, they’re likely to have little or no impact on how far off you can hear or scent someone. (In fact, sounds may even travel further in mountainous regions due to echoes.) As you noted, that can be a prompt for the GM to improvise other ways that the PCs detect the presence of other creatures if they’re out of line of sight — but then, how do you determine how far line of sight extends in the wilderness? Do you make one roll for spotting distance and another (unaffected by terrain and vegetation) for other senses? I’m not sure it’s worth that much effort, though.
@wyvern, I’ve been to the arctic tundra (in winter, but still), low moss, very low hummock, low shrubs (1-3ft), prob some grass or sedge, but not when I was there, occasional 10-15′ high dense bushes. Possible stands of trees, depends on how far north you are. I think having less visibility than plains is ok, but there is a huge range of tundras.
Counting tundra as a fen, string bog, or low moor, all sound about right.
I naturally overcomplicate systems, so I’d tend to what you suggest, but it may be more appropriate to reverse out the specific local terrain from the general category result, if this roll is the zoom-in mechanic.
N.B Some rulesets state that encounters in the wilderness are in yards not feet. This means if you haven’t been adjusting, encounters have been happening three times closer than they ought to have been.
When using battlemats, encounters start when both sides are on the mat. 🙂
So being aware of creatures beyond mat range (about 150′ for a typical 24×30 mat) I normally treat as pre-encounter with the possibility of evading the encounter. Only once you are on the mat do I use the combat rules, eg turns & movement by turn.
I looked in the 1Ed AD&D DMG and on P.49 it covers encounter distance. The only terrain that modifies encounter distance is Scrub, Forest and Marsh.
Also, the encounter distance outdoors is 6D4 X 10 yards.
Most of the discussion seems to be on “line of sight”.
The table states “encounter distance” though, so that doesn’t have to be just sight.
Encounter distance can be any of the five senses… but, by the time it gets to touch, I definitely think that counts as surprise!
If you’re imagining the terrain as very rugged, or the inside of a sinuous canyon, describe the encounter with sound or odor, or of it’s a flying/climbing creature maybe they’re just above.
Or, as Justin has said in other posts, don’t let the results from a procedural generation table be holy writ. If the result doesn’t work, throw it out. You had an idea about why it doesn’t work, use that impression to guide a choice instead.
Seeing some other impressions and ideas about how to incorporate the other senses into encounter distance has definitely helped me.