Dungeons and Dragons campaigns can end up spanning thousands of miles, with the party traveling from coast to coast, across mountains and through different planes of existence. Keeping the game interesting even when transportation spells aren't available yet is vitally important.
A long, lonely road is a great place for role play and getting your players to develop their characters and form bonds. You could run the typical bandit ambush or highway robbery, but if you're looking for something they'll never expect, throw one of these random encounters at your players to really get them thinking.
10 Shifty Traveling Merchant
Heading towards the party is a small coach with two horses, hurriedly driven onwards. Upon interacting with the sweaty driver, the players may determine that he's in a rush and trying to get away from a mob that's chasing after him. The salesman has been visiting small towns and villages, selling Wyvern Oil in exchange for valuable possessions from desperate townsfolk.
If the players refuse to let him leave, he's willing to sell the possessions at a massive discount and continue to outrun the angry mob. Many of these items are mere trinkets and silverware, but if they sift through the junk, the party can uncover common magical items..
9 Moral Quandary
Beyond the treeline, the party spots a dark plume of smoke caused by a terrible house fire. Upon arriving at the scene, they're met with a large crowd of bystanders, all holding buckets but not helping to extinguish the fire. Two individuals are desperately trying to save the large house alone, begging for others to help. The bystanders will explain that this is the wealthiest property in the region, and the family heavily taxes the locals.
They also point out that gold doesn't burn, and are planning to ransack the remains once it's died down. Whether the PCs snatch the villagers' buckets to do a good deed or stand and watch it all go up in flames, this will hopefully spark a debate about the characters' moral standings.
8 Surprise Party
On a quiet track through the woods, the party finds themselves abruptly pulled up into the canopy in a large blanket. As they struggle and try to cut themselves out of the trap, they hear excitable voices and celebratory cheers. It's not long before the wrapped-up party is deposited onto the ground again, and the blanket stripped away to reveal a sea of innocent faces that quickly become shocked.
A group of friends had planned to "kidnap" their buddy, Ash, for a surprise birthday party, and Bernie had been sent to make sure that Ash and some other friends were on this specific path at this specific time. What a massive misunderstanding! Hopefully none of your violent adventuring party managed to hurt these misguided partiers. They're invited to attend the party as an apology.
7 Ominous Rock
It's pretty hard to miss it, far off along the road, maybe in the plains or the mountains, there stands a ten-foot tall boulder. It seems to be made of obsidian, sharp and warm to the touch. When approached, the rock hums gently, and if knocked upon, it sounds a little hollow.
The party has found the ominous rock. To add even more mystery, residents of the closest village might warn the travelers about the rock, whispering folklore and mumbling prayers of safekeeping. The big secret about this rock is that it's a normal rock. There's no magic, no cool backstory. If the adventurers don't leave it alone, then maybe the big rock of paranoia ends up as the campaign's big bad. Watch them obsess over a totally inert stone in the road.
6 A Haunting Display
Some ways along a forest road, the most perceptive player hears soft knocking coming from the woods. Upon investigation, the party finds a 50-foot tall fir, so covered in clean bones that it's difficult to see the tree itself. Hanging from the underside of the lowest branches are animal pelts, and other gory viscera depending on the hardiness of your friends.
If someone is brave enough to disturb the roots, they'll find heaps of nicely wrapped gifts. Boxes and parcels tied up with string, shiny and new, sitting in stark contrast to the horrors displayed above them. Who decorated the tree? Who placed presents around it? How long has it been like this? Come up with your own answers, or leave it as a mystery to haunt the party.
5 Couple's Counseling
Soon after setting off at sunrise, the party come across a heated argument. Two individuals scream accusations and curse at each other. If the party intervene, the couple explains they agreed to a duel at dawn to sort out who is in the wrong. They've tried to settle it amicably, but neither trusts the other at this point.
She is convinced her husband only agreed to marry her to get access to her family's vast estate, and now he intends to sell it to bail his own failed business out and divorce her. He retorts angrily, accusing his wife of making a deal with the local mage, forcing him to fall in love and propose against his will. Now the spell has faded, and he wants compensation for his business failing. You can add to this story or change some details, and let the party decide if and how to help the couple.
4 A Good Deed
At the edge of town, a young Dwarven girl can be heard singing to passersby, hoping for some coin to feed her and her siblings. She isn't getting much positive attention, though, as her singing voice is gratingly poor. Spiteful teens jeer at her from the other side of the street, but run off when the adventuring party comes near.
The girl refuses the players if they try to give her a large sum of money, stating that they must have worked hard for the money, and she must do the same. The team might try to teach the girl a different performance to entice people, such as juggling or a gambling game.
3 Questionable Combat
Ambushes on the road are a common occurrence, but for something a little more interesting, a lone Goblin jumps from the bushes along the road. They initiate battle with the strongest looking adventurer. The blows the Goblin lands are non-lethal, and its heart doesn't seem in the fight.
If they decide to question it, the party learns that the Goblin was meant to be chaperoning a group of children through a dangerous forest. Upon hearing the approach of a rival Goblin clan, the chaperone hid "like a coward", and let the children be kidnapped. The Goblin, feeling guilty and shameful, intends to return to its own clan and claim that it tried its best to fight off the attackers, but it needs to look like it's been wounded first.
2 Fairy Ring
When the players look for a clearing to make camp, they stumble across a ring of brightly colored mushrooms. With a high enough Nature or Arcana check, it's revealed that this is a teleportation circle to the Feywild. Stepping within the ring and presenting the mushrooms with a small gift will whisk the individual off to a similar Fairy Ring on the Feywild plane.
This can be used for quick travel to random places in Faerun, as the magic in the Feywild can mean stepping in the same Fairy Ring will send you to a totally different place.
1 Creepy Companion
For a truly unsettling adventure, after a long night's rest, the players find that their luggage has been rifled through. Things have been removed from bags and turned upside down, as though someone was searching for something. After a thorough check, nothing is missing, except the party's nerve.
Each night, whenever someone fails a 20 perception check, an invisible Brownie darts out from behind the treeline and quickly searches some belongings. It never seems to find what it's looking for, but for a few nights, it will be all the adventurers can think about. This is a minor encounter, meant to give the dungeon master a little kick!