Why Cypher Works Alone
The Cypher System Rulebook is written for a GM and a group of players, and it has no solo chapter. But one of Cypher's core ideas makes it a natural fit for solo play: the GM never rolls dice. Every NPC, trap and hazard is just a level from 1 to 10, and you roll against it. Playing alone, you never have to roll for the other side or decide whether a villain's attack lands. You set a number and roll your own d20, exactly as you would at a table.
What's left is the GM's other job: answering questions and throwing in complications. Cypher already has a tool for the second one, the GM intrusion. For the first, you need an oracle.
The One-Person Writers' Room
Earlier parts compared Cypher to improv, where the rules support the story instead of slowing it down. Playing solo, you're both the improviser and the audience. The oracle plays the role of your scene partner: it says "yes, and" or "no, but", and you build on whatever it hands you.
What You'll Find in This Part
- A yes/no oracle built on Cypher's own d20 roll and difficulty steps, with exact odds
- Scene checks and self-intrusions that keep the story surprising
- How to run NPCs, combat and cyphers when you're also the GM
- A step-by-step routine and a worked example for your first solo session
Your Solo Kit
- A d20 and a d6, or the task roller in the Digital Toolkit.
- The rules. The free Cypher System Reference Document (CSRD) has the core rules; the Cypher System Rulebook adds everything else.
- One character, built with character creation or picked from the Character Library.
- A notes file or index cards for NPCs and their levels, places, open questions and threads.
- A journal. Writing the story down is half the fun of solo play, and it's how you remember threads between sessions.
đź’ˇ Tip: General-purpose GM emulators such as Mythic Game Master Emulator (Word Mill Games) work with Cypher too. This part sticks to an oracle built from Cypher's own d20 roll. For solo play in general, see Ray's Solo RPG Mastery guide.
The d20 Oracle
The oracle works just like a task. Ask a yes/no question you genuinely don't know the answer to, decide how likely "yes" is, and roll a d20 against the matching target. Each step of likelihood is one difficulty step: 3 on the die, or 15%.
- Very likely: 5 or higher
- Likely: 8 or higher
- Toss-up: 11 or higher
- Unlikely: 14 or higher
- Very unlikely: 17 or higher
Then read the roll:
- Natural 20 → Yes, and… Yes, plus something extra in your favor, like a major effect.
- Target +2 or more → Yes.
- Exactly the target, or 1 over → Yes, but… Yes, with a complication or cost.
- 1 or 2 under the target → No, but… No, with a consolation or an opening.
- Further under → No.
- Natural 1 → No, and… No, and things get worse, just as a natural 1 brings a GM intrusion.
The Odds
Every number on a d20 is equally likely (5%), so these odds are exact:
| Likelihood (target) | No, and… | No | No, but… | Yes, but… | Yes | Yes, and… | Any yes |
|---|---|---|---|---|---|---|---|
| Very likely (5+) | 5% | 5% | 10% | 10% | 65% | 5% | 80% |
| Likely (8+) | 5% | 20% | 10% | 10% | 50% | 5% | 65% |
| Toss-up (11+) | 5% | 35% | 10% | 10% | 35% | 5% | 50% |
| Unlikely (14+) | 5% | 50% | 10% | 10% | 20% | 5% | 35% |
| Very unlikely (17+) | 5% | 65% | 10% | 10% | 5% | 5% | 20% |
The table mirrors itself: "Likely" is exactly as likely to say yes as "Unlikely" is to say no. A toss-up is a true coin flip. And because the "but" answers sit right next to the target, close calls always bring a twist instead of a flat answer.
🎲 Try the Solo Tools
Session Log
- Your rolls will appear here.
Running Scenes Solo
A solo session is a chain of scenes. Each one starts with what you expect to happen and ends when its question is answered.
The Scene Check
Before each scene, decide what you expect to happen, then roll a d20. This is a simple house rule inspired by GM emulators, not a Cypher rule:
- 1–2 (10%): Interrupted. Something different happens. Use a random spark or your character's background for inspiration.
- 3–7 (25%): Altered. The scene happens, but one detail is different: someone extra is there, the place has changed, or the timing is off.
- 8–20 (65%): As expected. Play it as you imagined.
Running NPCs and Challenges
This is where Cypher shines for solo play. You never roll for the opposition, so all you have to decide is a number.
Set the Level Before You Roll
Give every NPC, creature, lock and hazard a level from 1 to 10 when it appears, and write it down. The target number is always level Ă— 3, eased or hindered by your skills, assets and Effort as usual. If you can't decide on a level, ask the oracle: "Is this guard a veteran?" Yes might make it level 4, no level 2. Once a level is set, don't change it because a roll went badly.
Let the Oracle Speak for NPCs
Cypher has no reaction table, so use the oracle. Set the likelihood from what the NPC wants and what your character has done: "Does the merchant believe my story?" is Likely if you paid well and Unlikely if you were caught lying. If you try to persuade them, that's a task like any other: roll against their level, eased by your skills and Effort.
Combat
Run fights as written. Roll to attack against each foe's level, and roll Speed defense (or Might or Intellect defense) when they attack you. Track their health and your Pools honestly. To decide what a foe does next, pick the move that fits its goals, or ask the oracle: "Does the beast flee once it's hurt?"
Intrusions, XP and Cyphers with One Player
- Intrude on yourself. Whenever the oracle gives a "but" or an "and" that hurts, or when a scene feels too easy, make it a GM intrusion: a complication arrives and you earn XP for accepting it. At a table you'd keep 1 XP and give 1 to another player. Solo, a simple house rule is to keep 1 XP and give the other to a companion NPC if you run one.
- Natural 1s. As at any table, a natural 1 on a task is a free intrusion with no XP.
- Reward discoveries. Cypher gives XP for discoveries, not for defeating foes. When the oracle reveals something important (a hidden door, a secret, a strange device), award yourself XP the way a GM would.
- Use your cyphers. Hand yourself new cyphers often, roll them randomly from the rulebook or the Digital Toolkit, and respect your cypher limit. Solo play with a full set of cyphers you never use is just as dull as at a table.
- Advance as normal. Spend 4 XP per character advancement, and reach the next tier after buying the four main ones.
⚠️ Watch out: The most common solo mistake is never intruding on yourself. If nothing ever goes wrong unless the dice force it, your story will feel flat. Take the complication and the XP.
Building a Character for Solo Play
- Cover the basics. A solo character needs a way to fight or escape, a way to talk, and a way to find things out. Pick a type, descriptor and focus that cover gaps between them.
- Edge is your stamina. With no party to share the load, cheaper Effort matters. Favor the Pool you'll use most.
- Bring a companion. Some foci and abilities give you an ally or companion. Solo, they're someone to talk to and someone to watch your back.
- Pick a focus that starts stories. A focus like Explores Dark Places or Hunts Outcasts pushes your character into scenes. One that only works in a lab or a library can be harder to play alone.
🛠️ How To: Your First Solo Session
- Make one character, or pick one from the Character Library.
- Write a one-line problem. "Someone is stealing relics from the old ruins." That's the session's question.
- Frame the opening scene. Where are you, what do you want right now, and what's in the way?
- Roll a scene check. Adjust the scene if it's altered or interrupted.
- Play. Give everything a level, roll tasks against it, ask the oracle about everything you don't know, and intrude on yourself when the story needs a twist.
- Close the scene when its question is answered. Note new NPCs, discoveries and open questions.
- Repeat until the problem is solved or you reach a good cliffhanger. Then award XP for discoveries and write a short journal entry.
Example of Play
Whisper Nightshade, from the Character Library, is "a Stealthy Explorer who Explores Dark Places". For this example, she's trained in sneaking and in searching ruins, and she has a Speed Edge of 1. She's looking for whoever is looting the old ruins.
Scene: Whisper expects to slip into the ruins at night. Scene check: 5, Altered. She decides the entrance has a fresh campfire beside it: someone is already here.
Question: "Is anyone awake at the camp?" It's late, so it's Unlikely (14+). Roll: 13, one under the target: No, but… Everyone is asleep, but a tethered hound lifts its head.
Task: The hound is level 2, so sneaking past is difficulty 2. Whisper is trained in sneaking, which eases it to difficulty 1: a target of 3. She rolls 11 and slips past without spending any Effort.
Intrusion: Inside, the scene feels too easy, so Whisper intrudes on herself: the floor of the old hall gives way beneath her. She accepts and takes 1 XP. Catching herself is a difficulty 4 Speed task (target 12), eased to 3 because she's trained in moving through ruins (target 9). She applies one level of Effort to ease it to 2 (target 6), which costs 3 Speed minus her Edge of 1, so 2 Speed. She rolls a 7 and hangs on to the edge.
Discovery: Below the broken floor is a sealed chamber nobody has opened in centuries. That's a discovery, so she awards herself 1 XP and starts the next scene there.
Common Questions
Isn't it boring to know everything already?
You won't. The oracle, scene checks and intrusions answer the questions you'd normally leave to a GM, so you discover the story as you play. Only decide what you would decide as a player.
What if the oracle gives an answer that makes no sense?
Reinterpret it before you roll again. A "yes" that seems impossible often hides a twist. If it truly breaks the story, treat it as a "but" answer or ask a smaller question.
Should I play one character or a whole party?
Start with one, perhaps with a companion. Cypher is light enough to run two or three characters, but each one adds Pools, cyphers and XP to track.
How do I avoid fudging for my character?
Set levels before you roll, roll in the open (even if only you can see), track your Pools honestly, and intrude on yourself when the story needs it. When in doubt, ask the oracle rather than choosing.
Key Takeaways
- The GM never rolls in Cypher, so playing alone you only need to set levels and roll your own d20.
- The d20 oracle uses difficulty steps: targets of 5, 8, 11, 14 and 17, with "but" answers right at the target and a natural 20 or 1 for "and".
- Scene checks and random sparks stop you from writing a story you already know.
- Intrude on yourself, take the XP, and reward discoveries the way a GM would.
- Use your cyphers freely, and advance with 4 XP per step as usual.
đź““ Journal Prompts
After your first solo session, jot down:
- Which oracle answer surprised you most, and what did it change?
- When did you intrude on yourself, and was it the right moment?
- Were any levels too easy or too hard?
- What discoveries and open threads do you want to follow next time?