How to Adapt a Group RPG System for One Character Without Rebalancing Everything Yourself

Decide what “one character” means at your table

First pin down the format. In solo play, one person controls the protagonist and also makes or interprets decisions for the world. In one-player, one-GM play, the GM still handles the world, but the protagonist is the only player character. The first format needs procedures for uncertainty; the second may need few or none. Both need an adventure shaped around one protagonist’s choices.

Write down the character’s strengths, likely gaps, and the adventure’s main kinds of challenge. A scout in a wilderness mystery may need little combat support; a spellcaster exploring a locked ruin may need a way to deal with physical obstacles. This short diagnosis prevents unnecessary changes. Do not add a companion just because a standard party in the game usually has one.

Keep the core rules and change the adventure’s assumptions

Preserve character creation, checks, equipment, advancement, and other procedures unless a specific rule fails at the table. Instead, revise the situations that depend on several characters acting together. Replace “each hero covers a different task” with obstacles the protagonist can approach in multiple ways: negotiate with the gatekeeper, find another entrance, recruit temporary help, or spend a resource to bypass a barrier.

Treat party-dependent scenes as questions of access and consequence, not just difficulty. If a group adventure expects one character to notice a clue, another to read a language, and a third to speak to a local, a solo version can let the same character investigate all three avenues. A weak skill can still matter: a failed roll might cost time or attract attention rather than stop the story altogether, if that fits the game’s existing failure rules.

This is an adaptation principle, not a claim that every published adventure can be used unchanged. A tightly scripted scenario may assume several characters are present at once, or may rely on a capability the protagonist lacks. In that case, change the scene’s fictional setup or use a relevant game rule; do not silently grant success where the rules call for a consequential roll.

Use an oracle to answer questions the GM would normally settle

In solo play, an oracle is a compact procedure for resolving questions whose answers are uncertain to the player. Ask questions that can be answered clearly, such as “Is the archive door already open?” or “Does the ferryman recognize the seal?” Decide how likely “yes” is, use a suitable randomizer or table, and interpret the result in context. Keep ordinary character actions under the game’s normal rules; the oracle answers about the world, not whether a character succeeds at a skill check.

A published example is Mythic Game Master Emulator. Its publisher describes procedures for yes-or-no Fate Checks, open-ended Detail Checks, event checks, and NPC behavior checks. You can borrow the general idea without importing every part of the system: prepare a small likelihood scale, ask one specific question when you genuinely lack an answer, and let the result suggest a complication or detail. Word Mill Games’ Mythic Variations 2 describes those question types.

For example, Mira, a cartographer, reaches a lighthouse after sunset. She knows the keeper was expected, but not whether he is home. She asks, “Is the keeper inside?” and assigns the answer an even chance because nothing in the fiction points either way. A “no” answer does not dictate the entire scene: she might find a lit lamp, a note on the door, or tracks leading down to the shore. She chooses the result that best fits the established setting, then plays out Mira’s next action using the RPG’s normal procedures.

Avoid asking the oracle to decide everything. “What happens next?” is so broad that it can produce noise instead of direction. Ask one question at a time, record important answers, and stop rolling when the fiction already gives you a reasonable answer. If the result is surprising, add one concrete detail and continue rather than building an elaborate new subsystem around it.

Give the character support only where a real gap appears

A companion can provide a missing ability, another presence in a scene, or a story connection. Keep the companion’s job narrow. Decide what they are good at, what they need from the protagonist, and how much of their decision-making the player controls. A companion who can scout ahead but will not enter the sealed observatory gives the protagonist an advantage without solving every challenge.

If the game already includes companion or sidekick rules, use those before inventing a full second character. For one Dungeons & Dragons example, the D&D Essentials Kit rulebook includes sidekick roles called Expert, Spellcaster, and Warrior, with sample statistics and rules for gaining levels. Those are specific to that D&D product; they are not a universal template for other games. The official rulebook’s Appendix A shows how an existing game can give a companion a lighter, defined structure.

If no suitable companion rules exist, use a simple fictional arrangement: the companion can attempt one relevant task, has a clear limitation, and does not replace the protagonist’s major choices. For instance, a mapmaker’s hired guide might know the mountain paths but refuse to enter an old watchtower. The guide contributes knowledge and a reason to choose a route; the protagonist still decides whether to take the risk.

Do not assume a companion automatically fixes combat or encounter balance. A companion adds actions and may change how threats work. Keep an eye on how much extra attention the companion’s turns require, and avoid adding several helpers at once if managing them slows the game. When a companion is not needed for the current problem, let them stay behind, handle a separate task, or contribute through a brief narrative detail.

Replace party-sized obstacles with focused resolutions

When a scene assumes several characters can act in parallel, decide what the protagonist is actually trying to achieve and resolve that objective at the level of detail the game supports. A party fighting a dozen animated suits of armor might normally involve many turns. In a solo narrative session, the protagonist could instead try to reach the control dais, collapse the gallery doors, or hold off the guardians long enough to escape. Use the game’s existing rolls and consequences to decide the outcome.

This does not mean every large threat should become one easy roll. Keep the stakes visible. A failed attempt to reach the dais could cost a shield, separate the character from an ally, or trigger an alarm—provided those consequences fit the game’s rules and fiction. If the encounter’s tactical detail is part of the fun, retain it, but reduce the number of active opponents or give the character room to retreat, bargain, or change the terrain.

For noncombat scenes, use the same method. Instead of requiring a party’s separate social, investigative, and technical specialists, make the goal clear and offer more than one route. To recover a stolen observatory lens, the character might persuade the apprentice, search the workshop, or trade a favor. Each route should draw on the system’s normal mechanics and create a different cost or piece of information.

Use a repeatable procedure for uncertain scenes

A small loop keeps solo play moving without extensive preparation:

The loop is a practical synthesis, not a rule from a single published game. Its benefit is that each tool has a job: the RPG resolves the protagonist’s actions, while the oracle supplies prompts about the world. If a result does not create a useful choice, revise the question or move on instead of rolling repeatedly for a more satisfying answer.

Adjust only after you see a recurring problem

Play a short opening scene before changing character statistics, adding extra actions, or rewriting encounter math. Note what actually stalls: no way to get a clue, too many enemies acting before the protagonist, a missing skill that blocks progress, or uncertainty about what an NPC does. Make one targeted adjustment and try the next scene.

For example, if a locked door repeatedly stops the adventure because the character has no relevant skill, add a second route or let the character seek help in the fiction. If combat consistently overwhelms the protagonist, change the encounter’s objective or number of active foes before increasing the character’s damage. If you are unsure what non-player characters do, use a behavior prompt or a clear motive rather than controlling every detail by instinct. The appropriate fix depends on the rules and the scene; there is no universal adjustment that makes every group game balanced for one character.

Keep a brief session note: what went smoothly, what felt cumbersome, and what rule you changed. If a fix solved one unusual scene but made later scenes too easy, revise it. The goal is a playable version of the game you already enjoy, not a perfect mathematical conversion.

When to use a solo-first game instead

Some group RPGs rely heavily on party roles, tactical action economy, hidden GM information, or long sequences where several characters must contribute at once. You can adapt them, but if each session requires repeated redesign, a game built for solo or GM-less play may be a better fit. For example, the official Ironsworn page describes tools and prompts intended to move adventures forward with or without a GM, and its rules are presented for solo, cooperative, or GM-guided play. That is one option to explore, not a requirement to abandon your preferred system. Shawn Tomkin’s Ironsworn page explains the included prompts and flexible play formats.

A useful test is whether the challenge is the adaptation itself or simply learning a new way to run scenes. If you enjoy your current game’s character options and resolution rules, keep it and adjust the specific friction points. If you spend more time managing missing party roles than playing the character, try a solo-first system or a lighter companion framework.

A practical starting checklist

Before the first session, decide whether you are playing solo or with a GM; identify one likely gap; choose an oracle only if you need one; and prepare a scene with at least two ways forward. Start with the normal character rules. Add a companion only if a specific story or rules need calls for one. After the session, change the one thing that caused the most friction.

This approach avoids rebuilding a game around a hypothetical party. Keep its familiar procedures, reshape the scene’s assumptions, and add a small tool only when play shows you what is missing. A single protagonist can then face meaningful choices without requiring you to recalculate an entire system before the story begins.

Sources

Keep exploring this topic