With good game design and the odd tweak to the math side of things, D&D 5e can be enjoyed as a two-player experience. One player in charge of a single character, and one Dungeon Master doing the usual DM stuff. Some people call adventures written this way “duets”. 

Naturally, what works for true solo play mechanically can be easily ported to a duet experience, so solo gamebooks are good resources for duet players and DMs.

BEOWULF AGE OF HEROES

This Ennie Nominated complete package of mechanics, setting and adventures is the work of a team of industry veterans led by The One Ring’s Jon Hodgson. It takes the tale of Beowulf, one of the oldest in western European tradition, and turns into a uniquely duet-minded hack of 5e built around the original class of The Hero, which branches off into six ability-score-based subclasses.

In this DrivethruRPG Electrum bestseller, you progress by amassing an NPC following as well as levelling up, and there is a ton of support for online VTT play. You can have a taste of it with the free intro scenario they make available here.

IN THE HEART OF THE FOREST

This DM’s Guild Platinum bestseller tasks the 5th or 6th-level player character (or four-PC-party, there is material to run it both ways!) with investigating the disappearance of 10 druids out of the original 11 that made up the local druid circle. Something is wrong in Blackwoods forest—Undead abound and a festering evil threatens the land far beyond its borders.

This Brainchild of Jonathan and Beth Ball (of D&D Duet fame) features NPC sidekick classes, and special mechanics for adventuring with sidekicks

FIRST BLUSH 

This is D&D Duet’s first adventure, a pay-what-you-want DM’s Guild adamantine bestseller is meant to kickstart your duet campaign with a 1st level player character who is a person of means and some social import, summoned to an important diplomatic event. It features plenty of roleplay, and the combat is mostly low-stakes until the climactic battle at the very end.

This adventure is self-contained, but there are sequels should you decide to keep playing on along the tracks laid by Jonathan and Beth.

THE YEAST HEIST FIASCO GETAWAY

To wrap it up, let’s look at a hidden gem. The 5th level player character is the last survivor of their crew after a botched heist, and their goal is to skip town while being hunted by authorities, other criminals, and even unaffiliated actors. 

There are several avenues for progression and any one “questline” can be abandoned in favor of another—consequences apply—in a way reminiscent of the level design you can find in immersive sim videogames like Arkane Studios’ Dishonored. 

It is complex to run, but plenty of aids are provided for the DM’s convenience and the complexity is highly rewarding for both parties but especially the player.