View Full Version : Outdoor adventures and random encounters

2013-08-12, 03:27 PM
Since googling around got me to lots of old forum threads that all went Sandbox! Sandbox! Hex-Crawl!, this is not meant to be about hex-crawl games, but regular (though open-ended) plot-driven adventures. Just set out in the wilds instead of the city.

I suddenly found myself with some people eager to start a Pathfinder campaign and I want to use this as an opportunity to give my homebrew setting another run (the last one was at a very early concept stage and more like some elements I had in mind set in a generic world). It's a world where civilizations consists of small villages banded together in clans, with 90% of the land being more than 3 days of travel from the next settlement and roads are pretty much nonexisting. So unless you are staying in a village or are inside a dungeon, the PCs are going to be outdoor in the open wilderness, and will spend a lot of time there. So I think it should also be a major part of the game.
Taking an example from the probably best known fantasy novels, both the Hobbit and The Lord of the Rings consist of almost nothing but traveling through the wilderness and dealing with random encounters, that end up being a lot more complicated than 4 rounds of combat. I also love the idea of Dark Sun, from which I am heavily drawing, and people frequently mention that the worst enemy is the environment itself. Now I won't be having so much heat and lack of water, but I still would like to implement the wilderness as a danger in itself. Unfortunately, the Dark Sun box doesn't seem have any more advice on that either.

However, I really have no experience with that at all and usually skipped any random encounters, since I tended to think of them as "just another 4 rounds of combat before the story continues". But now, I want those events on the journey to be an important part of the story itself. Looking on some of the older AD&D "modules", I also like the idea of dungeons as "sites" which the PCs can explore in any way they want. The story-driven adventures common to D&D 3rd Ed. and Pathfinder usually have dungeons that are one long (winding) corridor that leads to the "boss" at the end.
So for this campaign, I want both the wilderness and the dungeons to be an environment in which the PCs have a task to complete and not to be an almost fully-planned string of combat- and puzzle-encounters.

And I've come to think that random encounters are a very important key element for that. And players have to know that they are not pre-scheduled in advance. Otherwise the encounters are just another thing that is inevitable because the GM says that they have to deal with it before they can continue. And here I am running into a bit of a problem. I think the most interesting part of the game is to judge situations, make descisions, and deal with the consequences. If the random encounters are truly random, than the players have no way to influence what happens to the PCs and any of their descisions are just as meaningless as if I schedule for the party to run into 4 dogs on the third day.
But as I said, I never really used random encounters before and those tables found in 3rd Ed. books seem to assume "here are X number of creature Y. Kill them". So I am rather lost about what to do with them. Any words of advice?

2013-08-12, 03:52 PM
First off, make a really, really good to scale map and have an idea how far things can travel around on a day to day basis.

Second, write up actual encounters. Actual random encounters are boring, feel impersonal and just don't make for a fun day. Make it like, a goblin chieftan with his shaman and a small band of goblins are looking for somewhere to settle, and you can encounter them for example. However, instead of saying the party definitely encounters them, have them around on the map, and the party has a chance to meet them if they get close to where they are, or have the encounter move near to the party.

This lets the party talk to the people in town who may have heard rumours of say, a goblin, or they can tell the party to stay away from a haunted stream where a vengeful banshee dwells. This means that even though the party may or may not encounter anything, it is something they can influence, it makes towns more interesting, and it means the encounters build up the world rather than just being there.

2013-08-12, 04:11 PM
Having random environmental encounters that don't boil down to a few skill checks and are an important part of the story seems like it would be very hard to do well. I think I understand what you're going for, but I'm not sure how to implement it.

First, you want your encounters to be thematically appropriate for the specific environment you're in. Second, and more problematically, you want them to be complex and engaging, which is very hard to do in D&D. The vast majority of environmental hazards can boil down to one or two skill checks. For instance, a sudden storm might be a dramatic event in a story, but in a game, the ranger can just make a Survival check to find shelter to wait it out (or to keep going and avoid getting lost). If you try to roleplay it, you run into problems if the players don't know the first thing about wilderness survival.

If you're prepared to design complex encounters, you can make dynamic and engaging "environmental" encounters. But then you're getting away from the random encounter idea, unless you're very good at coming up with ideas on the fly.

The only suggestion I can come up with at the moment is to create several encounter tables, each one with a different type of encounter. For instance, you might have one table for terrain obstacles/hazards, one for weather/environmental events, and one for combat encounters. Then, you could start by rolling to see what types of encounters happened. So you roll, and you see that you get a terrain obstacle and a combat encounter. Roll on those tables, and you see "river gorge" and "black bear." Then, with a little imagination, you can hopefully come up with an interesting way for the bear to disrupt the characters as they're crossing the gorge, and/or for the gorge to complicate the encounter with the bear.

Even if that makes for more interesting encounters (and I don't know if it would work), it doesn't necessarily solve the underlying problems with random encounters. I don't know that it makes them more meaningful in the context of the story, and the variety can still be exhausted pretty quickly if you're not careful.

2013-08-12, 04:39 PM
My I advice is to think of every encounter, as a mini plot-hook. Think of something that will spike the player's curiosity or evoke a strong emotional response. Also something in the encounter might serve as a Chekhov's Gun (http://tvtropes.org/pmwiki/pmwiki.php/Main/ChekhovsGun) to return to later in the main campaign.

Some random encounters I've used with success:

- dangerous creature X... "4 rounds of combat" ... followed by bumping into said creature's nest/lair with eggs just about to hatch or some young cubs (used in three times by me so far, always ending with a new party mascot and once an animal familiar for one of the players)

- a meteorite - the players see the flaming trail in the night sky, then feel the ground shudder (in my adventure the meteorite carried alien organisms that were a cross between Finaly Fantasy and The Thing - they started out invisible energy beings, but when contacted blood, they infested it and turned manifested physically as random deformed creatures.). The meteorite could be the source of some amazing new metal, but it weights a ton, and the low-level players have no means of transporting it (but will come back to it several adventures later once they find a high-level weaponsmith that dreams of getting his hand on some star metal)

- a lone druidess in the forest - quaint little hut in the middle of nowhere, a bit of a witch vibe, the players don't know how a lone woman survives in the forest and whether to trust her invitation (in my case they trusted her, and benefited from a good night's rest, some good food and herbal supplies and a romantic one night stand out in the woods... that will have its consequences 9 months later)

- a body of a boy murdered in some gruesome manner... and on him an unfinished letter to his mum about him going to seek out his dad's buried part of the loot (so many plot hooks here - find the killers, find the boy's mum, find dad's lost treasure)

- a group of golems and constructs running along a path with mine carts full of ore (can be followed to a master artificer's little fortress)

- a small wizard's tower that seems abandoned but still has some magical protections on it

- a primitive stone altar with traces of a bloody human sacrifice from just a few nights ago.. and lots of tiny little footprints...

2013-08-13, 10:24 AM
I am thinking that actually a lot could be learned from old-school hex-crawl and dungeon-crawl campaigns.

After all, the only real difference is that you would be traveling through hexes and exploring a specific hex because you are looking for a dungeon you know has to be somewhere around that area, and you explore dungeons because you are looking for a specific object or person there. The only thing that is different is that you can stop exploring when you have reached your goal and go home without the hex or the dungeon being cleared.
But otherwise, the way that traveling and exploring works would be just the same. And sandbox games seem to have come very much into fashion in the last couple of years. There should be quite some stuff to learn from.

Kol Korran
2013-08-13, 10:43 AM
Hmmm... I like this thread. If I can Summarize your issues, I think they boil down to these?
1) You want to know how to use the wilderness itself better to challeng the players.
2) You want to have meaningful random encounters, that include the elements that makes a game interesting- meaningful decisions with consequences. (I fully agree with you on that).

I'll share my opinions, starting with the second issue: First of all I think it is wrong to call these "random encounters", since this mostly gives an impression of "unrelated to the scene" encounters. I prefer to call these "Extra encounters"- encounters that are not a must, but that can add a lot to the main story. This does not mean they are unplanned, unrelated, or do not have a consequence other than "beat the creature, get XP, loot the gold".

I think that you can divide extra encounters to 4 types:
1) Ones that help establish the material you have in your planned plot. For example meeting scout group of the big bad's advancing army. Or meeting friends of potential allies, or coming upon a site that may have info about a destination the party seeks and so on, if handled correctly.

2) Ones that add to the flavor and theme of a place. These are especially suitable for journies through interesting settings, and getting a feel for them. The idea is to add to the place they are in NOW, and that these interactions may have effects in the CURRENT situation. Like If the party is going through a stone giant territory, and an old monument of the stone giants, who might in fact harbor a guardian spirit of the old race, watching them hidden, or meeting a few young stone giants trying to capture wild griffin eggs in order to rear them, Or perhaps a hermit "Thunder caller", a sort of shaman/ oracle for the tribal community.

3) Things that gives a bit more flavor to the world at general. I'm talking like pilgrims from far away, or a merchant with tools of an ancient country, or maybe an outsider that somehow got to the material plane and now lives amongst mortals and such. I like to tie these somehow to what the party already knows and have an interest in. These add flavor, but do not directly affect the game, though they may have quite long reaching affects (Like by a tool/ cohort/ feat gained). These fit a long campaign, or a world the players have begun to know well.

4) I always have one final category for things that don't need to have context, but are just a plain fun idea to toy with. These ideas are good enough to keep, but not good enough to make it into the main plot, and don't quite fit elsewhere. So if they pop up it's nice, as a diversion.

The way I approach extra encounters is by helping me flesh better, give more life to a specific adventure/ scene. I'll try to give a simple/ cliche example, perhaps it might even fit with the very little I know of your world. Lets say there is an adventure that takes the PCs into "The Hunger Woods"- an old ancient forest, who is known to be sinister and deadly, where armies of old fought long ago, and it was cursed by... something, and few that traverse it pass through it. The forest is said to grow dark red at night, with the blood of those who died in it. (And so on and so forth, we know the drill...)

Now, Make whatever forest navigation rules you like, and whatever random tables you like of the following (Perhaps with adjusted percentages for different parts, perhaps even for day and night), And here is a few of potential "Extra encounters" Who might make them just as important to the game as the "main meal":
The Blood hosts: The forest is known for it's pack of stirges, who hide and follow those who pass, and seek an opportunity to descend upon them, hunt them, while they are distracted.
Purpose of Encounter: flavor for the forest, focusing the "blood theme", deal with a "pest" element.
Challenge: Find a way to deal with the pests. Just shooting at them won't help much. (Cover, small size, huge numbers), such a pack notices the party, but doesn't attack. It instead follows them, and tries it's best to avoid them if pursued, only to follow again. The stirges will attack the least armored party members as soon as they are: fighting some other monster/ crossing a stream mid waist/ climbing/ while most party sleeps (In this case the stirges will sneak on the ground to the targets, drinking from them while sleeping)
Fail: The stirges get enough blood drunk (not good for the party) and leave them be. They are wise enough not to kill their food storages. (Unless they get a bit too... overexcited. :smallwink:)

Trolls trunks, Faerie rings: For some unknown reason, in the more ancient parts of the forest, trolls appear in the night, hunting fiercely. Rumors may suggest these are some spirits locked in the trees themselves, made of bark and wood, the anger of the trees, or their agony, unleashed upon the world at nights.
Purpose: Deal with a nightly relentless predator, fidn a secure place of sleep. And perhaps deal with the mystery of who these trolls are, what made them so.
Challenge: Unless the party finds a way to throw the trolls of their scent, or a secure place (Like special faerie rings tied to their mystery), The trolls have a good chance of ruining a good night sleep, and haranguing the party. The ancient tree spirit that harbor the trolls may have a special place amongst the forest powers, and depending how they are treated these may affect other interactions, or even gain special knowledge or favors.
Fail: The party just have to fight off the trolls when they come, and probably get little if any sleep. When moving to another sector of the forest, roll again. Oh, and in the day the trolls retreat back to their trees.

Ancient Battle Site: Across the forest are strewn the long lost remains of the armies that fought here long ago. some echoes and spirits may still linger.
Purpose: provide flavor, provide clues of what is to come.
Challenge: To understand more of the few visions that are displayed, perhaps interact. The remains of the battle scene may have old armor, standard, and other tools of the fighting forces. But it also harbor remains of spirits. These may still enact part of the battle, or perhaps bemoan something they need be done (Not a fully mini quest, but something simple like putting a skull back, or saying a prayer over their body, or take up their sword, so it will still be of use), but they speak in an old tongue, not easily understood. Or perhaps they don't use words, but figments and lights and images. To make it more interesting there may be a few spirits here, of opposing sides. Who will the party help? They may get some sort of boon, or an ill omen by the spirits, or perhaps they lean a secret? or perhaps some essence of the dead, that may help later?
Fail: Either nothing happens, or some minor curse by a spirit.

"Accidents may happen. We make sure they due!": (Inspired by the "accident" power of Shadowrun spirits. The forest has a few bestial malevolent spirits who likes to play pranks, deadly pranks upon those who trespass on their turf.
Purpose: Similar to the Stirges encounter- enhance the flavor of deadliness, but fro ma more supernatural power. Interesting challenge on how to appease a spirit.
Challenge: The spirit (Whatever that may mean in your world, I'm thinking of a trickster sort of nature bound fey with a deadly sense of humor) takes an interest in the party. It follows them and makes mishaps far more painful. If the party misses by more than a 5 on a physical check (be it a climb, swim, attack and so on), they cause some kind of mishap to themselves, after which a loud aloof but unrestrained inhumane laughter could be heard. If not dealt with, these grow worse, and worse, and worse. The party needs to find ways to deal with the spirit (I suggest to make it not just a simple fight, but have to come up with a creative idea. I'd let the players try and break their heads on that). The spirits may know a lot that goes on in the forest, and let slip of it's information during conversation, made to harass competitors, be an ally, or be angered to a lot worse.
Fail: After enough amusmenet has been had from the party, or if they do not prove entertaining enough, the spirit leaves to find new prey.

The Devourers: It is said that deep in the forest lie twisted misbigotten creatures, between humanoid and wolf, all hunger, who can consume you entirely, body, mind and soul. Beware the devourers!
Purpose: This can really be any type of creature, though in the example I"m talking about some sort of modified Barghests. The idea is that the place the party travels to in the forest, In the main plot, not "Extra encounters" may have these creatures, and this is a sort of a primer fight against them, as well as being able to (less likely) talk to them. It's a promo basically.
Challenge: This one is simple- fight a few of the relevant creatures. If they are intelligent, it may be imperative to stop them from escaping (so not to alert their party). It might be also useful to catch them and interrogate them). If less intelligent, Still a lot can be learned from this fight.
Fail: Depends on the fight, the creatures and situation.

"We're not alone": The forest has more than one brave party adventure in it, but they may not be all after the same causes...
Purpose: Give a bit more flavor for other groups interested in the forest, and also a conversational challenge in the midst of exploration.
Challenge: The party meet a group of strangers. Give them a purpose that differs enough from the players as not to be buddies with them, but to accept a limited cooperation. The idea here would be to get along well enough to gain info, (Possibly on other random encounters as well) possibly some tools and such (odorous paste to ward off stirges?) and so on.
Fail: "Guess we'll be on our way then..."

The blood pore: Some forests have hidden traps, such as sink holes, or crash pits. This forest as the blood pores.
Purpose: An "Environmental hazard" that is supposed to keep the party at edge, add flavor and strengthen the "blood theme", and provide an interesting challenge in regard of a magical affliction.
Challenge: The party stumbles on a well hidden natural rupture )like a mini geyser) or plant that spouts out a blood red cloud on a few characters. Roll saves etc etc... It can have various effects- a sickness, a condition of flying into rage when bleeding, of not healing well, or more. SHould be a special condition to the forest. Other than just dealing with it and trying to get over this, there might be an added complication of trying to seek help (Like a local shaman), or special antidote, and the choice of whether to give time to deal with this and heal, or to marshal on? (Interesting decision if there is a time pressure)
Fail: Depends on the effect.

2013-08-13, 11:11 AM
Hmmm... I like this thread. If I can Summarize your issues, I think they boil down to these?
1) You want to know how to use the wilderness itself better to challeng the players.
2) You want to have meaningful random encounters, that include the elements that makes a game interesting- meaningful decisions with consequences.

Yes, that very much. :smallbiggrin:

2013-08-13, 12:02 PM
There are all sorts of opportunities in a wilderness setting! Lots of good suggestions have been made already, but here are a few more:
-Something attacks their camp at night (this could be affected by whether they chose to take shifts guarding, etc, and would certainly encourage them to do so in the future)
-Traveling commoners ask for protection (maybe they're secretly running drugs, and helping them gets them in trouble with the town guard when they finally reach civilization?)
-A wandering madwoman/madman that gives them riddles
-Having to intervene in a Druid vs. Lumberjack melee

2013-08-13, 12:08 PM
Found these articles (http://thealexandrian.net/wordpress/17308/roleplaying-games/hexcrawl) while looking around. Havn't read them all, but seem to be very on the crunchy side of things.

I am thinking about writing up a really quite extensive list of short blurbs of situations into which the characters could be running and make encounter lists out of them.
Things like "1d6+2 3rd level warriors, 10% friendly allies, 60% neutral, 30% hostile" or "an abandoned hut with a skeleton under the rags on a bed in the back corner". Those wouldn't be the whole encounter, but just a starting point to make up something on the fly. It doesn't even have to start immediately, but you can make a 5 minute preparation break to think about any special touches to make the encounter interesting. Like saying the warriors are wounded survivors from a battle, or adding a trapdoor to the hut that leads to two dire rats and a magic bow.

Kol Korran
2013-08-14, 01:05 AM
I am thinking about writing up a really quite extensive list of short blurbs of situations into which the characters could be running and make encounter lists out of them.
Things like "1d6+2 3rd level warriors, 10% friendly allies, 60% neutral, 30% hostile" or "an abandoned hut with a skeleton under the rags on a bed in the back corner". Those wouldn't be the whole encounter, but just a starting point to make up something on the fly. It doesn't even have to start immediately, but you can make a 5 minute preparation break to think about any special touches to make the encounter interesting. Like saying the warriors are wounded survivors from a battle, or adding a trapdoor to the hut that leads to two dire rats and a magic bow.

Oh, so you are taking a more "random" approach indeed... Why do you think these add that much to the game? What is their added value? Why would the PCs care about the neutral wounded warriors they happen to pass, or the abandoned hut? How does it add to the gaming experience?

2013-08-14, 07:39 AM
I don't know that yet. That's what this thread is about. :smallbiggrin:
But I think for player descisions to be meaningful, it needs to be established that not everything they encounter has been hand-picked by the GM who had already decided what opponents they will face at what point.

I found a couple of interesting articles on the subject, which I yet have to dig through entirely (and probably reread a second or maybe third time), but that look very promising:
Hex Crawling Encounters (http://www.paperspencils.com/2012/03/08/hex-crawling-encounters/)
Making travel more engaging (http://www.paperspencils.com/2012/03/05/making-travel-more-engaging/)
You're everything a Big Bad Wold could want (http://trollsmyth.blogspot.de/2011/09/hex-mapping-part-17.html)

Jay R
2013-08-14, 10:07 AM
Taking an example from the probably best known fantasy novels, both the Hobbit and The Lord of the Rings consist of almost nothing but traveling through the wilderness and dealing with random encounters, that end up being a lot more complicated than 4 rounds of combat.

More importantly, they aren't random. In The Hobbit, the random encounters are:

Trolls. The purpose is to scare Bilbo, show that the dwarves, though greedy, are ready to defend their companion, demonstrate that power can be wisdom, not strength, and to provide Thorin, Gandalf, and Bilbo with magic swords.

Elves: They visit Rivendell to reveal the secret of the map.

Goblins: To separate Bilbo from the dwarves to set up his solo adventure, so he alone will know about it.

Gollum: To provide the major magic item of the story.

Goblins at the door: To show that Bilbo is developing courage, and to show him that the Ring works.

Goblins and wolves: To make them hurry away.

Spiders: To show Bilbo's growing competence.

Elves: To generate enough animosity for a major battle.

Every "random" encounter is in fact a crucial part of the story.

Similarly, you should know why each encounter happens. I ran a wilderness adventure, and I knew exactly why the animal migration, orcs, unicorn, rust monsters, witch, evil high priest, scorpions, dragon, giant ants, djinn. camels, pirates, and gryphons were encountered where they were.

Some were there so they could pick up important magic items, some to justify why nobody else had made it along this path for a long time, some were consequences of the region's history, two were there to show that evil beings weren't always either on the same side, or your enemies. (The witch and the Evil High Priest were personal rivals. The PCs helped the witch against the EHP, and were able to move on, with her thanks and all the EHP's items that she couldn't use.)

I also had a few actually random encounters, but they were mostly animals or other monsters suited to the environment, and their primary purpose was to keep the party alert, and make it feel like a wilderness.

2013-08-14, 10:47 AM
I think that's getting things backwards. Ignoring that it's a novel where the writer has a general idea how things are supposed to turn out in the end, those encounters influenced how the adventure progresses and had an impact on how everything ended. But they were neither planned, nor neccessary stages of the quest to complete the adventure.
Neither the party nor the people they meet intended for those encounters to happen, and from what I remember correctly, it wasn't as if those people where stationary at their locations. Had the party taken a path just a few hundred meters to the side or passed by those places half an hour earlier or later, the encounters would not have happened. And in those scenes later on, when the results of earlier encounters became a benefit to the party, the characters could also have found different solutions to their problems.

I think the lesson to take away from this is, that random encounters don't have to be pre-scheduled, but that they can enhance the rest of the game to a great deal, if the events of those random encounters have an effect later on.
Fighting a group of goblins and one of them escapes could lead to the goblins sending out a patrol to catch the PCs. If the treasure from a random encounter includes a magic item, it can come very handy in a later situation and even be a life-saver. If the PCs think back and say "we should have gone after that goblin" or "what fortune that we found that scroll of knock", then they become meaningful additions that enhance the game.

some guy
2013-08-14, 11:16 AM
Something to take in mind; random encounters don't tell a story about the pc's (until the pc's get involved), they tell a story about the world.

Instead having 1 d100 table make several, smaller random encounter tables (d8 to d20, depending on how large you want it to be). Make 1 small table per region (Like Kol Korran already noted; if you're up to it, you could make 3 tables per 1 region; 1 for on the road, 1 for in the wilderness, 1 for nightly encounters).
Then, when the pc's ask about the region, you could have npc's tell things as "Stick to the roads, the Woods of Desolation be full of basilisks!" or "Only travel in broad daylight, at night your own shadow comes alive in the Bogs of Misery."
You might even, when the pc's ask about a region, roll on the random table for a bit of information (if you use Gather Information you might grant extra information about the table).
Also, have always more than one way to the pc's goal. Have those ways lead through seperate regions, let the pc's know about the difference: "You want to go the ruins of Aldervale? Well, the fastest way is through the Scary Hills, but the thickets are teeming with cockatrices. Another path leads through the High Mountains but people get abducted by kobolds there. So, even while it's the longest route, you might want to take the Adjective Road; there's only an occasional bandit there."

Oh, so you are taking a more "random" approach indeed... Why do you think these add that much to the game? What is their added value? Why would the PCs care about the neutral wounded warriors they happen to pass, or the abandoned hut? How does it add to the gaming experience?

Is it not the players responsibility to take an interest? And if they don't, that's fine, just move on. Not caring or interacting with a possible encounter might have consequences, it might not. I'm perfectly fine with players ignoring things. But that creates also something. Sometimes you get little gems like "Oh, dang! You guys, remember that wounded elf we ignored? I bet that was totally related to [plot point X]." "Oh damn! You might be right!" "I told you we should interrogate her!" And then the GM can chuckle a bit. Players are perfectly capable in creating their own story.

2013-08-14, 11:52 AM
What I am planning is basicaly "hex-crawl with a plot". The PCs don't want to go to any hex and see if there's a dungeon in which they clear all the rooms, but they are trying to reach a specific hex to find a specific object or person in that dungeon.
But I think when it comes to the mechanics of travel and exploration, it will still be just the same as in an old-school sandbox game. The PCs travel through a world, not a series of challenges set out specifically for them. That means they have the freedom to plan and chose their route, and to find a way that leads them to their goal. Without random encounters, they can chose how the tracks are laid, but the railroad will still stop at all the stations the GM decited. While in the end it doesn't make a difference if they accidentally run into a monster too strong for them or if the GM puts that monster there with the anticipation that they will flee from the fight, I think it's really important for the experience of the game, that the players know that there is a difference between planned and random encounters.
It's a difference if the players debate "we could take the shortcut through the sewers, maybe we are lucky and don't run into the fiendish otyugh" or if they debate "we could take the shortcut through the serwers, maybe the GM decited he will let us pass without trouble".

What I am planning is to come up with encounter tables for each type of environment encountered in the setting of the game (arctic, plains, forest, jungle, marsh, hills, mountains) and have each consist of 32% wandering monsters, 24% natural obstacles (landslide, flood, broken bridge, ...), 16% wandering NPCs, and 8% artificial structures (ruins, hunting lodges, guardposts, ...). The remaining 20% are left open for encounters specific to the current location or plot, like additional encounters with giant spiders in the spider forest, additonal encounters with undead on a haunted battlefield, or NPCs from a hostile faction hunting the PCs. Those I'll write up when I prepare for the specific session.

I really like the idea of making adjustments for staying on the roads, going offroad, or trying to stay out of sight. Since for my campaign road travel will be very rare, that would be a good example for additional special encounters on the encounter lists. Things like additional bandits and traveling merchants.
But I also think about adjusting the chances of having an encounter at all. The chance for an encounter per interval could be 40% normally, but when traveling on the roads the chance increases to 60%. When trying to stay in cover, it drops to 30%. At the same time, using the road would make the characters travel faster while sticking to cover would make them go slower.
That way, player's would actually make a risk assessment and have to decide whether to travel quickly or safely.