Human in front, planner behind.
The choice that organizes everything else is the role split. The Game Master is the only person at the table the players ever interact with. The voicing, the improvisation, the table feel, the tonal calls. All of that stays human, because that's where the warmth of a TTRPG session comes from. A bot at the table doesn't work. Players can tell instantly.
Throughline sits behind the curtain. While you're running the game, it's tracking the long arcs, the NPC consistency, the canon you and the players have established across sessions, the callback opportunities buried in the transcript. It thinks several scene-beats ahead and proposes what the next moment could look like. But it never speaks at the table, never makes a ruling, never narrates to anyone but you.
The Game Master is the actor. Throughline is the writer's room.
Why storyboards, not text.
The planner has to communicate its proposals fast. A Game Master mid-session has maybe ten seconds of attention to spare on whatever the planner sends back. A paragraph of prose is a minute of focused reading. You can't read prose at the table.
A small grid of three images is the right bandwidth: wide for the room, medium for the dynamic, close for the detail your players will reach for. Your eye picks up posture, expression, lighting, props, mood, ten visible details, in a glance. Whatever the planner wanted to say in prose can be encoded as visible elements in the frame instead.
We started with text. Every Game Master who tested it ignored it. The storyboards are what made the product land.
Raise the floor, not the ceiling.
Throughline is not for the best Game Master you know. It's for the rest of us.
The best Game Masters in the hobby, the ones who prep three hours per session, voice every NPC, and run season-long arcs whose payoffs land months later, already do everything Throughline does manually, with years of craft behind it. They don't need a planner. Asked directly, the best Game Master we've played with told us so.
But most people who'd love to run a campaign that good can't. They don't have the time. They don't have the years of practice. They don't enjoy the prep enough to spend three weekly hours on it. Throughline is for them: the people who can run a great table when they get to one, but who can't always plan the world the table deserves.
The goal is to make a deep, open-world, callback-rich campaign possible for the Game Master who'd love to run one but doesn't have the bandwidth to build it alone. We're not trying to replace the people who already run great campaigns. We're trying to invite more people into the room.