How to make a 3D game with AI prompts
Write one prompt in CityVibe3D, let the AI generate game code and a 3D city, then edit the scene and publish a browser play link.
What the prompt is actually doing
CityVibe3D is a browser tool for making playable 3D games from a written description. You do not install Unity, Unreal, or a local toolchain. You open the editor, describe the game in plain language, and the AI writes game code, builds an editable 3D environment, and connects characters and props into that scene. The result is one project you can keep editing and, when it feels right, publish as a link anyone can play in a browser.
A useful prompt names three things: the fantasy, the place, and the action the player repeats. “A neon street race through a night city” is a start. “A night-time street race. The player drives a car along glowing roads, steers with the arrow keys, boosts with the space bar, and scores points for near misses with traffic” gives the model a camera, a control scheme, and a win condition. CityVibe3D uses that description to generate the city layout and the gameplay script together, so the roads you see are the roads the car drives on.
Step 1 — write the prompt
Start in the editor and say what the player is. A person on foot, a car, or a jet each pull in different assets and different default controls. Then say where the game happens. CityVibe3D is built around a 3D city, so streets, blocks, bridges, and districts are the natural setting. Mention time of day and a color mood if you care about them: golden hour over the river, or rain on a downtown grid. End with the loop. What does the player do every few seconds, and what ends a run?
Keep the first prompt to one game. If you ask for a racing game that is also a fighter and also a city builder, the code and the scene will fight each other. You can add systems later by prompting again inside the same project. The first message should be specific enough that a friend could play it from your description without asking what the buttons do.
Step 2 — read the scene, then change it
When generation finishes you are looking at a real scene, not a mockup. Buildings, roads, bridges, and regions stay editable. Open the building tools to change floors, facade color, and windows. Open the road tools to drag path nodes or change width in meters. If a bridge lands in the wrong place, move it or prompt a new crossing instead of starting the whole project over. Characters and vehicles are linked into the scene; you can preview their animations and swap materials before you publish.
The generated script is editable too. Power users can open the code. Everyone else can tune live parameters such as move speed and jump force without reading the file. If the car feels slow, change the number and play again. If the camera sits inside a tower, say so in a follow-up prompt: “Move the camera behind and above the car, and keep the nearest buildings shorter than eight floors.” Follow-up prompts are how you correct the game. They are not a failure of the first try.
Step 3 — publish a play link
Publishing packs the scene and the game code into one browser game. You get a link. The other person does not install CityVibe3D and does not need an account to play. Send the link in a chat, put it on a page, or open it yourself on a phone to see whether the controls still make sense on a small screen. If something is wrong, go back to the project, change it, and publish again. The link is the game people play; the editor is where you keep working.
Before you share widely, play the loop yourself three times. Check that the player can start, can fail, and can tell why they failed. Check that text on screen is readable and that you are allowed to use any name or likeness you typed into the prompt. The Terms of Service cover what you may publish. If you are showing the game on a public CityVibe3D page, keep it suitable for a general audience.
A short example you can copy
Try this shape, then replace the nouns with your own: “Endless runner on a city street at night. The player is a person who runs forward automatically, slides left and right between lanes, and jumps over barriers. The street is straight, with low shops on both sides and a few taller towers in the distance. Score is distance. Hitting a barrier ends the run and shows the score.” That prompt has a genre, a control scheme, a camera you can infer, a place, and an ending. After it generates, shorten a few buildings, slow the run if it feels unfair, and publish.
You do not need to write code to finish that game. The code is there if you want it. The point of the prompt is to get a playable scene quickly, then spend your time on the parts you can judge by playing: speed, readability, and whether the city looks like the place you described.
When you are ready to try it, open the CityVibe3D home page and launch the editor.