Entertainment

AI in Video Games: How Game Worlds React to You

By Eri-Tech Global Ltd · Published November 1, 2026 · Last updated November 1, 2026 · 9 min read

Close-up of hands holding a black game controller against a brown background.
Hands holding a black game controller.

AI in video games is changing what happens when you talk to a character, walk into a town, or try a new way through a level. In older games, most of what a character said was written in advance. A shopkeeper had a set list of lines, and you heard the same ones each time you visited. New AI tools give some characters more room to respond to what you actually do and say, within limits set by the people who made the game.

What AI in video games means

The phrase AI in video games covers a wide range of tools, and that breadth causes much of the confusion around it. At one end, AI helps people build a game: suggesting code, drafting a first version of dialogue, testing a level, or filling in routine art and animation work. At the other end, AI runs inside the finished game. It decides how an enemy moves, what a shopkeeper says when you return, or how a companion reacts when you change your plan.

Older games already used AI, just not the kind that writes sentences. For decades, designers used rules and decision trees: if the player is close, the guard moves closer; if the player is hurt, the enemy presses its attack. Those systems were predictable, which let a designer test every path.

Language models add a different option: a character can form a reply from the current situation, rather than picking from a fixed list.

Characters that answer instead of repeating lines

The clearest example of a live AI character is the non-player character, often shortened to NPC. These are the people and creatures in a game world who are not controlled by a player: the innkeeper, the guard, the companion, the rival. In many games, their lines, known as barks, are short phrases triggered by an event, such as entering a room, starting a fight, or passing by on a street.

Ubisoft's research team, La Forge, built a tool called Ghostwriter to help with exactly this kind of writing. According to Ubisoft, Ghostwriter produces first drafts of barks, and scriptwriters then choose and edit the versions they like. The writer creates a character and a type of interaction, and the tool proposes variations, offering two options at a time for the writer to compare. After thousands of such choices by people, Ubisoft says the tool becomes more effective and accurate. The main story stays with human writers; the tool takes on repetitive first drafts.

A newer step is the character that answers during play, not only on paper. NVIDIA's ACE system is a set of tools for in-game AI characters. In a developer post dated 27 October 2026, NVIDIA said its newest small language model for this work, Nemotron 3.5 Bolt E4B, runs on the player's device, uses a 4GB runtime memory budget, and can use facts from the game itself, such as an inventory item or a quest step, rather than guessing. NVIDIA also said the model supports 35 languages.

NVIDIA gave two public examples from 2026. PUBG rolled out AI teammates in a public beta powered by an earlier Nemotron model. Aniimo, a game built around AI pets that respond to a player's voice, used a second-generation model and is set for release in early 2027, according to NVIDIA. A separate report by Tech Times, covering the same NVIDIA update, added that Mecha Break became the first shipped game with an NVIDIA ACE-powered NPC earlier in 2026. Each example gives AI a defined job, rather than handing it the whole game.

A young man in a cap playing a video game on a couch with a controller.
A player gaming on a couch with a controller.

Worlds that change with how you play

Studio Atelico, an independent game studio, opened early access on 29 October 2026 to an engine built for this kind of play. According to GamesBeat, which interviewed the studio's chief executive, Piero Molino, the Atelico AI Engine runs language models, image generation, speech systems, and character behaviour entirely on the player's device, and it works with the Unity, Unreal Engine, and Godot engines. Its Character Behavior System lets developers define a character's persona, backstory, relationships, and motivations, while collecting memories that shape later actions.

Atelico's own first game shows the other side of the same engine. In Bobium Brawlers, a turn-based card and dice game, players describe a character in plain language and receive a portrait and a playable deck made on their phone. GamesBeat reports that the game itself has not been released yet, and that the studio has not announced any outside customers for the engine. That detail matters. A tool can be promising in a studio's own game and still be unproven in other teams' hands. Early access means developers can request access and try it, not that it is already a standard part of how games are made.

There is also a practical reason on-device play matters. When AI runs on the player's device, there is no wait for a server to reply, and no fee for each answer sent to a cloud service. GamesBeat notes that Studio Atelico argues this keeps player data on the device. The trade-off is that the model must fit alongside graphics, sound, physics, and animation.

The quiet work behind the scenes

Most AI use in games never reaches the player as a talking character. It sits in the daily work of making a game: writing code, drafting text, testing, and planning. Unity's 2026 Game Development Report, based on a survey of 300 developers who use the Unity engine, gives a useful picture of that balance. According to coverage of the report by Wccftech, 62% of those developers use AI tools for coding assistance, 44% for writing and narrative design, and 40% for NPC behaviour. Market research followed at 37% and automated playtesting at 35%. Only 5% said they do not use AI at all.

A second report on the same Unity survey, by GamesMarket, lists the same top figures and adds context about project size. It says 52% of developers surveyed now focus on smaller, more manageable projects, and that 46% spend between one and three months on prototyping. Smaller teams with shorter projects gain the most from tools that speed up first drafts and routine checks.

Wccftech also adds a caution. Its coverage notes that the survey does not specify whether the AI-assisted work ends up in the final game, or whether it is used for prototypes and drafts that human developers later replace. A team can use AI to draft dialogue, test a level, or suggest code, and still ship a game in which every line and system was reviewed, edited, and approved by people.

The same caution applies to efficiency claims. Wccftech reports that 79% of developers at studios with more than 150 team members said AI tools helped them improve efficiency. That is a self-reported survey result from larger studios, not a measured count of hours saved across the whole industry.

Where it still falls short

Live AI characters bring problems that scripted lines do not. A scripted line can be checked once and trusted to stay the same. A generated reply can be wrong about the game's own facts, can repeat itself, can break character, or can say something the developers would not approve. That is why the examples here all keep a person in charge: Ubisoft's writers choose and edit drafts, NVIDIA's tools use facts from the game itself, and Atelico's engine adds filters so outputs stay within the game's own rules. None of these checks removes the risk entirely.

Cost and hardware form a second limit. A model that runs on a player's device must share memory with the rest of the game, and players do not all own the same hardware. A feature that works well on a strong graphics card may run poorly on an older machine or a phone. NVIDIA's own comparison also needs care: Tech Times notes that NVIDIA compares Nemotron 3.5 Bolt's response quality with Gemma 4 26B, a model nearly seven times its size, but that this comparison comes from NVIDIA's own evaluation and had not been independently reproduced at the time of writing.

A third limit is trust. Players notice when a character's voice, face, or words feel wrong, and they notice when a studio is open about how a game was made. Ubisoft's Ghostwriter post stresses that the tool was built with scriptwriters and that writers keep control of the final text. A studio that explains where AI helped gives players a clearer basis for judging the result.

An adult man using a VR headset and controllers in a room with blue lighting.
A player using a VR headset and controllers.

Frequently asked questions

What is an NPC in a video game?

An NPC, or non-player character, is a character in a game that is not controlled by a player. It may be a shopkeeper, a guard, a companion, or a rival. In older games, NPC lines were written in advance and picked from a fixed list. Newer AI tools let some NPCs form replies from the current game situation, within limits set by the developers.

Do AI characters mean writers are no longer needed?

No. The examples in this article keep writers in charge. Ubisoft's Ghostwriter produces first drafts that scriptwriters choose and edit, and NVIDIA's and Atelico's tools work inside rules, characters, and facts set by developers. Writers still shape the story and the final lines in the main plot.

Will AI characters work on any device?

Not yet. On-device characters must share memory and processing power with graphics, sound, and physics, so performance depends on the player's hardware. Cloud-based characters avoid that limit but add waiting time and running costs.

AI in video games is best understood as a set of tools with different jobs, not as a single change that replaces how games are made. It drafts lines, helps with code and testing, and lets a small number of characters answer and remember within rules set by people. The strongest examples so far are narrow, tested, and open about their limits.

If you play games, a useful next step is to notice where a character surprises you and where it repeats itself, and to ask what the developers have said about how that character was made. If you make games or content, start with one small, testable job, such as drafting background lines or testing a level, and check whether it saves time without weakening the result. For help turning a small idea into steady content, see Eri-Tech Global Ltd's services or get in touch through the contact page.

What to watch next

Watch for more on-device character tools reaching real games, and for studio reports on what worked and what did not. The real test is a shipped game where AI characters stay in character and remember what matters.

Sources

  1. NVIDIA Developer Blog — NVIDIA RTX Spark Powers Neural Rendering and AI Characters in Games — date checked: 2026-11-01 — https://developer.nvidia.com/blog/nvidia-rtx-spark-powers-neural-rendering-and-ai-characters-in-games/
  2. Ubisoft News — The Convergence of AI and Creativity: Introducing Ghostwriter — date checked: 2026-11-01 — https://news.ubisoft.com/en-gb/article/7Cm07zbBGy4Xml6WgYi25d/the-convergence-of-ai-and-creativity-introducing-ghostwriter
  3. GamesBeat — Studio Atelico launches AI engine built to run on-device inside games — date checked: 2026-11-01 — https://gamesbeat.com/studio-atelico-launches-ai-engine-built-to-run-on-device-inside-games/
  4. Wccftech — Unity's 2026 Game Dev Report Points to Smaller Teams Making Games in Less Time With AI Handling Back-End Tasks — date checked: 2026-11-01 — https://wccftech.com/unity-2026-game-development-report-points-to-smaller-teams-making-games-in-less-time-with-ai/
  5. GamesMarket — 2026 Unity Game Development Report Released — date checked: 2026-11-01 — https://www.gamesmarket.global/2026-unity-game-development-report-released/
  6. Tech Times — NVIDIA RTX Spark Delivers On-Device AI Characters Rivaling Cloud Models 7 Times Larger — date checked: 2026-11-01 — https://www.techtimes.com/articles/329590/20261028/nvidia-rtx-spark-delivers-device-ai-characters-rivaling-cloud-models-7-times-larger.htm
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