Directable Video Game NPCs

David Parks describes his first experiment with Jev involving “playable” video game NPCs.

David Parks@dparksdev𝕏

My first experiment with Jev from @typesafeai. "Playable" video game NPCs. Tell one to explore, gather resources, or build a house. Override its directive and watch it change course. The NPC's next action choices and probabilities are visible live. https://t.co/1YdumKmIgg

Sep 18, 2026X postsView on X

A player can tell an NPC to explore, gather resources, or build a house, then override its directive and watch it change course. The NPC’s next action choices and probabilities are visible live.

Also filed under Games & real time

Steer a 3D Box with Goals
The build steers a 3D box with plain-language goals. An LLM plans each instruction, while TypeSafe Jev makes move, turn, and jump decisions in real time.
Benchmarks Jev on Pokémon Red
The project benchmarks Jev, TypeSafe’s fast decision model, against Jev paired with a GPT-6 Sol planner for playing Pokémon Red.
Plain-English Cellular Ecosystem Simulator
LifePot is a cellular automaton-inspired ecosystem that users describe in plain English. Jev turns those inputs into species, feeding relationships, reproduction strategies, and environmental conditions.
Mapping Children's Behavioral Intent in Games
Mores Research used Jev to map children’s behavioral intent in games and examine how it correlates with real-world behavior. It reports mapping intents across 45+ real sessions involving 20 child users over a long horizon.