AI NPC and Voice Command Mods: Game-by-Game Guides

Modders have been teaching game characters to talk for years. What has changed is how little code it now takes. With Neocortex, the character, its memory, its voice and the story beats it should hit all live in one browser editor. Your mod sends what the player said and what is happening in the game, and gets back lines, emotions and actions to play. This page collects our game-by-game guides for adding AI NPCs, Conversation Flows, quizzes and on-device voice commands to popular PC games.

What every guide covers

Each guide follows the same shape so you can compare games quickly:

• What you could build in that game: talking NPCs, guided story scenes, quiz characters, or voice-controlled companions.
• How the game is modded: the real script extender, plugin loader or SDK the community uses today.
• How Neocortex fits in: where the mod calls the Neocortex API, and where on-device voice commands take over.
• Getting started and mod policy, so your project stays within the publisher's rules.

Grand Theft Auto

• GTA 5 AI NPC mod: talking pedestrians, a voice-controlled crew and quiz side characters with Script Hook V .NET.
• GTA San Andreas and Vice City AI NPC mod: AI dialogue for the classic games through ASI plugins and CLEO.
• GTA 4 AI NPC mod: Liberty City characters that answer back, built on IV-SDK .NET.

Valve games

• Half-Life AI NPC mod: scientists and security guards that hold real conversations.
• Half-Life 2 AI NPC mod: talking citizens and squad voice commands with Source SDK 2013.
• Portal 2 AI mod: a test chamber narrator that reacts to the player and runs puzzle quizzes.
• Garry's Mod AI NPC and quiz addon: AI NPCs and quiz hosts in Lua.

Bethesda games and Cyberpunk

• Skyrim AI NPC mod: followers that talk, remember and take voice orders, with SKSE.
• Oblivion Remastered AI NPC mod: AI dialogue for Cyrodiil, with notes on the classic game.
• Fallout 4 AI NPC mod: companions and settlers with real conversations, through F4SE.
• Fallout: New Vegas AI NPC mod: Mojave characters with memory, built on xNVSE.
• Cyberpunk 2077 AI NPC mod: Night City NPCs and fixer calls with Cyber Engine Tweaks.

Strategy, sandbox and simulation

• Bannerlord AI NPC mod: lords, companions and battle voice orders for Mount & Blade II.
• Minecraft AI NPC mod: villagers that talk and tutor players, with Fabric or NeoForge.
• Stardew Valley AI villager mod: Pelican Town villagers with open conversation, through SMAPI.
• RimWorld AI colonist dialogue mod: colonists who talk about what just happened to them.
• Euro Truck Simulator 2 AI co-driver mod: a voice co-driver for long hauls, with the SCS SDK.
• Microsoft Flight Simulator AI co-pilot: a co-pilot that runs checklists by voice, through SimConnect.

Racing and co-op

• NFS Underground 2 and Most Wanted AI mod: a talking crew chief, race briefings and voice commands, with ASI plugins.
• Lethal Company voice commands mod: voice-controlled ship commands and an AI ship computer, with BepInEx.

Voice commands across every game

Short commands such as "follow me", "open the gate" or "pit stop now" should feel instant. Neocortex Voice Commands runs on the player's PC, works offline and understands natural phrasing, so your mod gets a clean command the moment the player stops talking. Read Voice Commands for Game Mods for how it works, and contact us for a Voice Commands license.

Start with one character

The fastest path in any game is the same: design one character in the Neocortex editor, talk to it in the browser until it sounds right, then connect it to your mod. AI characters, Conversation Flows and the API are on every plan, including the free one.

Checked October 2026. Neocortex is not affiliated with the publishers of the games mentioned on this blog.

Frequently Asked Questions