IP Red Lines for Vibe-Coded Games: 5 Rules to Keep Your Project Alive

The bottom line first: AI didn't change copyright law, only the speed at which you hit the wall

Fallout: New York taught everyone who wants to build games with AI a lesson: one person plus Claude Opus 5.5 shipped a browser game with "quests, dialogue trees, V.A.T.S., working Pip-Boy" in weeks — then got cease-and-desisted by Bethesda parent ZeniMax. Three days from viral to taken down.

Many people's instinct is "but it's AI-generated, so it should count as my original work, right?" — wrong. Copyright law doesn't care whether your production tool is a keyboard or an agent; it only looks at whether the output reproduces protected expression. AI merely floored the cost of making infringing products while pushing the odds of getting noticed to the ceiling: a viral demo is an invitation to the legal department.

Five rules below, each paid for by a real case.

Rule 1: Don't touch trademarks — names and domains are the hottest wire

The first thing ZeniMax's letter named was the fallout.nyc domain. Trademark infringement is judged far more bluntly than copyright: use someone's registered mark to draw traffic and imply official origin, and you lose almost every time. Renaming costs nothing; getting the letter costs the project its life.

In practice: on day one, do three things — check trademark registrations for your target name (every national trademark office lets you search free), use original names for domains and social accounts, and invent all in-game factions, currencies, and proper nouns. Remember: you homage the gameplay, not the name.

Rule 2: Clone mechanics, not expression — the "spiritual successor" is the only safe zone

Copyright protects expression, not ideas. Battle royale, deck-builders, metroidvanias — no company owns a genre's mechanics; but character names, plot text, art style, music, and boss designs are all minefields. AI is dangerously good at "learning too well": ask it for "a Fallout-like wasteland RPG" and it can reproduce the soul of V.A.T.S. and the Pip-Boy — which is exactly your most dangerous moment.

In practice: write into your agent prompts "original setting; forbidden from using any existing game's proper nouns, character names, or signature system names"; generate art procedurally or in an original pixel style instead of asking the model to mimic a specific game's look; write all story and dialogue from scratch — better corny than quoting.

Rule 3: "Free and non-commercial" is not a shield

This is where CHRIS FIRST fell in the most typical way: "It's all free and I make 0 money on it." But neither copyright nor trademark infringement requires commercial gain — free distribution still infringes; it only affects damages. Taking down a free infringing project costs legal one letter; rebuilding costs you weeks of life.

In practice: from day one, assume "this project will blow up" and build compliance to the standard of being seen by a legal department. Don't gamble on "we'll deal with it if it goes viral" — Fallout: New York proved the gap between 3.5 million views and the letter was 3 days.

Rule 4: Keep training data clean — don't feed the model original ROMs and scripts

Decompilation is a riskier genre than imitation. Maurice Heumann's MW2 decompile getting nuked by Activision surprised no one: decompiled output can hardly ever be washed into "my original work" — it's reverse-engineering of the original by nature. The subtler risk is on the input side: feed the agent unpacked assets from the original game, long excerpts from official wikis, or even let's-play subtitles as reference, and the odds of protected expression leaking into the output rise exponentially.

In practice: use only public, mechanics-level descriptions as reference ("what systems does this genre usually have"), never plot text or art assets; have the agent generate from a mechanics design doc from scratch instead of "remix this"; never let any file unpacked from the original game sit in your repo.

Rule 5: If the letter arrives, comply first — don't fight it

A cease and desist is not a court order — it's a warning letter. But ignoring it invites the other side to escalate straight to litigation. Individual developers and tiny teams have no capital for a war of attrition against a publisher's legal department. CHRIS FIRST actually handled it right: posted the letter, announced the shutdown, kept his dignity — and earned a wave of sympathy traffic.

In practice: take down the disputed content within 24 hours and reply in writing confirming it; don't publicly insult their lawyers (every tweet can become an exhibit); prepare a "rename + reskin" plan in advance — make trademark elements and signature systems configurable, so if trouble hits you can relaunch as a "spiritual successor" with a new name and art pack. That's real antifragility.

One-line summary

AI gives indie developers unprecedented output, but the bigger the output, the more you need self-imposed limits. The best homage is an original work that delights the original IP's fans while giving the legal department nothing to pick at — learn the mechanics, don't touch the names, keep assets clean. Hold these 5 rules and your game lives long enough to be remembered.