AI game master
An AI game master for you and your friends
Claude, OpenAI’s GPT and Gemini in one group chat. Pick a setting and a rules system, invite your party, and play together: the AI narrates, rolls in the open and keeps your rules and character sheets in the room’s Notes.
How it works
- Start a campaign roomPick the RPG campaign template. Before the first scene, the game master asks for your setting, rules system and tone, and waits until you say you are ready.
- Invite your partyShare one invite link. Everyone who joins sees the campaign so far and builds their character with the game master.
- Play togetherType @AI (or @Claude, @GPT, @Gemini) and what your character does. The game master narrates one beat, rolls openly and hands the spotlight around.
What it looks like
Lia
@AI I search the scrapyard for anything that still works.
Claude · AI
Investigation, d20: 14 + 2 = 16 vs DC 13, success. Under a rusted tram door you find a glove that hums when you touch it. Bruno, a patrol lantern is swinging your way. What do you do?
- Saved to Notes: Lia carries the humming glove (session 2).
Bruno
@AI I pull Lia behind the tram and hold my breath.
Claude · AI
Stealth, d20: 6 + 3 = 9 vs DC 12, fail. The lantern stops on the tram. Lia, the glove starts to glow. What do you do?
What you get
Notes the AI always reads
Rules, character sheets and canon go in the room’s Notes, which every AI reads before every reply, in every chat in the room.
Dice in the open
Every roll shows the die, the modifier and the target, and bad rolls stand. Prefer real dice? Post your roll and the game master uses it.
Claude, GPT and Gemini at one table
Ask whichever AI you like each turn, or ask all three for ideas and keep the best one.
Your language
Write in Portuguese, Spanish, Korean or any language you like and the AI answers in it. The app’s own menus come in 28 languages.
Polls for party decisions
Split the party or not? Put it to a vote in the room, and the game master can start one for you.
Bring an old campaign
Import a conversation from ChatGPT, Claude or Gemini and carry on in a room with your whole party.
Free AI replies every day. Your own keys, or credits from $5.
- 50 free AI replies a day on fast models
- Stronger models with credits from $5
- Replies bill to your own provider account, no markup
- Stronger models, pay as you go
- Packs of $5, $10, $25 and $50
- Plus 50 free fast-model replies a day
- About 549 Sonnet 5.5 replies per $5 pack, 0.9¢ each
- 1,000 fast-model replies a day: use the fast AI as much as you like
- About 1,600 smart replies a month on stronger models ($15 of credit); unused credit rolls over for one more month
- Friends in your rooms get stronger models from your credit, with a daily limit each
- Charged to the room owner, not per member
Questions
Can an AI really run a whole campaign?
For most groups, yes. The game master keeps the rules, character sheets and story so far in the room’s Notes, waits for the players during setup, and never decides what your character says or does. Long campaigns go best when you save the important facts to Notes as you play.
Are the dice rolls fair?
The game master shows every roll: the die, the modifier and the target number, and it keeps bad rolls. The rolls are made by the AI rather than by a certified random number generator, so if your table wants physical dice, roll them yourselves and post the result. The game master will use it.
Which game systems work?
Any system you can describe: d20 fantasy, horror investigation, narrative systems, or house rules you made up. Paste your rules and the game master saves them to the room’s Notes.
Can we play in Portuguese or another language?
Yes. The game master answers in the language your table writes in, and splitscreen’s menus come in 28 languages.
Is it suitable for teenagers?
splitscreen accounts are for people aged 13 and over, and the game master is set up to keep games suitable for teens.
What does it cost?
It is free to start: every account gets 50 free AI replies a day on fast models (GPT-6 Luna and Gemini Flash-Lite) once you verify your email. For stronger models, buy credits from $5 a pack. Or one person gets Squad for $15 a month: the whole $15 comes back as credit (about 1,600 smart replies a month), and friends in your rooms get stronger models from your credit, with a daily limit each. You can also bring your own API key, with no markup.
Bring your people
Create the room, invite your group with one link, and start. It is free to start.