After you’ve covered the basics of running 5e one-on-one, you’re ready to move on to step number two, adapting your game’s PC for this smaller-party play style! In terms of mechanics, one-on-one works best when you make sure the PC is flexible in both melee and ranged combat. This post covers a few different options for making these adjustments to the core classes.
Even with a more flexible PC, we still suggest adjusting the number of combatants to make sure that 1) action economy doesn’t get too imbalanced and 2) the PC has someone to talk to on their adventures. Ensuring that the small party isn’t drastically outnumbered will go a long way toward keeping combat engaging instead of overwhelming, and having a fellow traveler, whether animal or person, will allow them to engage in RP throughout and provide them with additional support in social encounters and exploration.
Adaptation #1: Boost Spells and Attacks with Magical Items
It’s always fun to receive a present perfectly selected for you. Crafting magical items unique to the PC—their personality, class, and subclass—will have precisely that effect for your player. As you’re just trying to please one person, you don’t have to worry so much about making sure the items are balanced across the characters at the table, though you may want to craft an item that can grow with the PC. They don’t need a legendary artifact at level 3.
So what types of items might help increase the PC’s flexibility without sending them over the OP edge? Let’s look at the three base types of PCs separately and extrapolate from there.
In general, casters in duet-style play might struggle to deal enough damage before their enemy does them in, especially if they’re in a melee situation or have had several combats in one day. You certainly want to challenge them to make creative use of their spells and other abilities—playing in a duet is amazing for encouraging creative problem-solving—but sometimes they’ll need a boost.
At the earliest levels, help give them a small bump to AC and some healing potions, and they should be alright. Once they hit level three, go through their spell list and see if there’s a cool spell that they might need in a pinch that they don’t want to keep prepared at all times like revivify, sending, detect magic, speak with plants, or counterspell. You can even ask the player for their thoughts on what their PC would like!
After you’ve selected the spell(s), play out the PC embedding the enchantment into an item over time or coming across a +1 weapon that would also let them cast the spell once per day without using a spell slot. These items also make great rewards from mentor characters at the end of a narrative arc, especially if you want them to have access to a spell that characters inside their class normally wouldn’t have.
For our fighting friends, you can go a couple different directions while keeping flexibility in mind. Do you want to make it easier for them to use their current skills and abilities, or do you want to give them access to magic they might not otherwise have?
One of the places where non-casters will tend to be weaker is in area of effect. Again, get your player involved here. Do they want to design traps so that they can infiltrate larger spaces with multiple combatants? You could use fog cloud as inspiration for the functionality of their smoke machine-esque device that they set up before sneaking around the cultists’ lair, and then they burst out of the fog or use it to hide in, slashing in whichever signature style they prefer.
Alternatively, a magical weapon with a small boost is everyone’s best friend. Perhaps their dagger can cast entangle once per day, or as in one of my favorite magical items we’ve ever used, you might give them a ring of returning which will boomerang their thrown weapons back to them.
We’re all thinking it, so let’s just say it: in many ways, these classes already have the best of both worlds for one-on-one play. By definition, they’re flexible and well-balanced, but this can bring its own problems, especially in boss fight situations. Depending on the build, your half-caster is probably going to lean more toward melee or ranged fighting, and they might also struggle with area of effect as we saw with the non-casters.
An additional struggle arises, depending on the PC’s class and that of their companion(s), when they’re facing creatures resistant or immune to nonmagical attacks. These encounters will be a lot more difficult and could even be impossible, if your half-caster doesn’t have a magical weapon. If they’re fighting werewolves with a standard, non-silvered longsword for example, they’re in for a really frustrating fight.
There are additional creative tweaks you might make, such as expanding a character’s range for their attacks without imposing disadvantage, or adjustments like having advantage on stealth checks when they’re in shadow.
Adaptation #2: Borrow from Other Subclasses in the PC’s Base Class
Consider allowing a PC to select features from more than one subclass when they level up. This is a tweak you’ll want to be careful with as not all subclasses are created equal in terms of their combined power in a single character. Generally, you should aim for abilities that would give characters an either/or type of bonus and avoid stacking advantages.
If we look at bards for instance, some subclasses allow them to have enhanced spellcasting options while others increase their fighting prowess, particularly in melee. They won’t be able to use both of these abilities at once and will need to choose if they want their action to be used toward spellcasting or a melee attack. PCs in large groups don’t need this increased flexibility, but it can open up in-combat choices and options for both players and GMs in one-on-one play.
Adaptation #3: Give Their Adventuring Companion a Unique Tweak
One of the functions of the PC’s adventuring companion is to help balance them out. If your PC is clanging around in plate armor, maybe their companion gains proficiency in stealth. You don’t need to go overboard here. Some of the boosts will depend on if it’s the GM or the player running the companion during combat and how fun the player will find these additional mechanics and strategies.
You can combine any and all of these adaptations to equip your one-on-one campaign’s hero to take on monsters and villains in all of their guises. Don’t be afraid to tinker and adjust as you go. Empower your PC, and they’ll surprise you with ingenious solutions to the nefarious hijinks you place along their path.
You can find more advice and ideas for one-on-one play at dndduet.com.