Shattered sky
A world-agnostic sandbox brain: people with routines who remember and act on their own, markets and supply routes, towns that grow and decline, seasons and festivals, creatures with territories, dungeons built as you explore, jobs from people who need them, enemies who learn, and a world that keeps moving whether you watch or not. Attach it to any world and live however you like.
People remember. Bonds change. The world keeps moving.
Bring any setting to life and live in it however you choose: fight, trade, build, scheme, explore, make things, settle down. People keep their own schedules, want things, remember what happened to them and act while you're elsewhere. Goods come from somewhere: a flooded mine raises tool prices two towns over a week later. Towns grow when trade flows and empty when it doesn't. Seasons bring planting, fairs, floods and hard winters; beasts hunt, breed and move; ruins reveal themselves one level at a time. The world notices what you keep doing and grows deepest there, with rivals, opportunities and trouble sized to your fame. Every scene is archived into a story record, so a promise made in week one still matters in month six. When a character's story ends, the world doesn't reset; it inherits.
Recommended GM model: GLM 5.3 Flash (a Core model, included in the plan; Craft marks it Slow). In live testing it followed the engine best: no behind-the-scenes notes in the chat, a header on every reply, and enemies who grow over time. GPT-6 Luna also works well and is faster. Avoid DeepSeek V4 Flash for this engine: it often leaves its working notes in the chat. Choose the model in the GM Model dropdown when you start a game.
World-agnostic and built to attach to existing settings. The engine supplies the procedures; the attached world supplies its cast, places, calendar and rules through a single World Settings doc. Before play, follow the Porting Guide and the Builder's Manual chapter "Attaching a World", and run the Engine Test Cases. Version 4 builds on the engine first proven in Steelsong, with ideas adapted from LIMBO, School Days, Gritty Realms, Isekai Reincarnation, Vaelaria, Dead Horizon, generative-agent research and classic story-pacing systems.