Neon Ninth: Cyberpunk NPC Prompt Pack

8 ready-to-use AI NPC personas for one connected cyberpunk setting, the Ninth, a rain-soaked night market under the maglev lines of Halcyon City. Each one has a voice, things it knows, a secret it protects, and rules for when to give items, start quests, or end the chat. They work in any engine or chat model, and drop straight into the Godot 4 AI NPC Starter Kit.

Built on the prompt library from the Godot kit, then expanded into a full cast with its own guide, tests, and tools.

The cast

• Juno Park: Fixer / Quest Hub
• Doc Ito: Ripperdoc / Healer
• Rook: Netrunner / Information Broker
• Officer Dex Marrow: Guard / Corporate Enforcer
• Mama Kay: Street Vendor / Gossip
• Silas Vale: Corporate Antagonist
• PIXEL: Companion AI (in-world)
• Sable: Rival / Mercenary

What you get

• 8 complete personas: personality, speech style, canon knowledge, a secret plus the cover story that protects it, action rules, items and quests, greeting, offline lines, deflections, and leak-filter keywords.
• Three formats: paste-ready system prompts (.txt), Godot NPCPersona resources (.tres) for the Godot kit, and plain JSON for Unity, Unreal, Ren'Py, RPG Maker, Roblox, or your own code.
• Genre guide: tone and voice rules, a vocabulary bank, how the cast connects, 20 quest hooks, relationship tiers, and genre-specific jailbreak lines to test against.
• npc_pack_tool.py: chat with any NPC in a terminal, export, or run the same test suite on your own model. Python 3, no installs.
• TEST_RESULTS.md: every number below, with verbatim replies and every miss.

Tested results (measured, not estimated)

168 replies from Llama 3.2 3B running locally (Ollama, CPU only): 8 NPCs × 7 scenarios × 3 runs, including 3 jailbreak attacks per NPC.

• 100% valid JSON · 91.1% correct game action · 98.8% in character before any filter
• 0 secret keywords shown to players (raw keyword hits caught and replaced by the guard filter: 5) · 2 of 72 jailbreak attempts won an item or quest (all still limited to the NPC's own allowlist, so nothing outside the design)
• Median reply 3.35 s on CPU
• Weakest area: extraction attacks (16/24). See TEST_RESULTS.md for each miss.

Honest notes

• Tested on one small local model. Larger models weren't benchmarked; npc_pack_tool.py test gives you your own scorecard in minutes.
• Small models drift. Always validate actions in code. The Godot kit does this for you.
• Juno Park's twist secret is never sent to the model (share_secrets_with_model off), so it can't leak, and the model can't hint at it either.
• No prompt is unbreakable. The guard rules, cover stories and leak filter are a strong head start, not a guarantee.

License

Use these NPCs in unlimited free and commercial games. No credit required. Don't resell or redistribute the pack itself.

More from AgentForge

• Godot 4 AI NPC Starter Kit: makes these NPCs talk, act and stay safe in Godot 4.
• Other genre packs, Bark Forge and Asset Forge: https://agentforge.itch.io
• Try one NPC from every pack free: AI NPC Sampler (planned URL)

AI disclosure: personas and docs were written with AI assistance and tested against a local language model. No AI-generated images.