I Tried To Make GTA 6 Using Fable 5.1

Summary
In this video, the creator behind the YouTube channel "Claude Knows My API Key" tests Anthropic's Claude Fable 5.1 by prompting it to build three playable browser-based 3D games (in Three.js) recreating scenes from the Grand Theft Auto VI trailer. Using escalating effort settings (Medium, High, and Extra/Max effort), he generates an Everglades airboat collectible run, a high-speed vehicle police chase with combat, and a skydive over a sprawling city skyline.

What is shown

• Introduction and Setup [00:00 - 00:25]: The presenter highlights Claude Fable 5.1's release announcement and benchmark scores on Terminal-Bench-Science 0.1, then sets up three challenges matching trailer scenes with Fable 5.1 effort levels (Medium, High, Extra/Max).
• Level 1: Everglades Run (Medium Effort) [00:26 - 01:54]:
  • Coding session stats: $56.38 cost, 1h 15m API time, +4,997 lines generated using Three.js [00:26].
  • First run displays a 3D swamp environment with dock and airboat, though the camera controls spin uncontrollably [00:35 - 00:54].
  • After code adjustment, gameplay shows steering an airboat through swamp channels featuring animated birds, swimming crocodiles, and a 5-marker checkpoint time-trial that unlocks a day/night cycle slider upon completion [00:57 - 01:42].
• Level 2: Police Chase / Heat Index (High Effort) [02:08 - 04:46]:
  • Initial generation tasks the player with driving and shooting simultaneously, resulting in physics bugs, extreme lag, and crashing [02:14 - 02:51].
  • After three prompt iterations, the player is placed in an auto-driven getaway car as a shooter: enemy police cruisers ram and flip, physics debris scatters, and a police helicopter engages overhead before being shot down with an "AIR UNIT DOWN" banner [03:14 - 04:35].
• Level 3: Skydive Scene (Max Effort) [04:47 - 06:26]:
  • Claude Fable 5.1 project session running a reference-matched Three.js city skyline scene [04:47].
  • Player character runs off an observation deck ~238 meters above ground and freefalls over a vast city with waterways and moving bridge traffic [04:54 - 05:10].
  • After debugging backward-bending arm animations, the player cleanly deploys a parachute with audio effects and glides down to street level [05:30 - 05:54].

Claims & numbers

• The presenter displays benchmark charts showing Claude Fable 5.1 achieving 49.5% at High effort and 52.6% at Max effort on Terminal-Bench-Science 0.1 [00:03].
• The Everglades Run generation session cost $56.38, took 1 hour 15 minutes of API time (1h 27m active), and generated +4,997 / -53 lines of code [00:27].
• The skydive jump is initiated from an altitude of approximately 238 meters above ground level [04:54].
• The presenter rates Level 1 a 3/5, Level 2 a 5/5 ("the first 5 out of 5 game that AI made in this channel"), and Level 3 a 4/5 [01:52, 04:24, 06:01].

Notable quotes

• "Today, I'm forcing Claude Fable 5.1, the newest and smartest AI model, to make GTA 6 from scratch." [00:00]
• "After playing this absolute chaos, I quickly realized that Fable 5.1 misunderstood how the game is supposed to be played." [02:53]
• "It's safe to say this is the first five out of five game that AI made in this channel. This is absolutely perfect." [04:22]

Assessment
This is a hands-on independent review and gameplay showcase evaluating code generation capabilities of Claude Fable 5.1. While the games run live in browser via Three.js and demonstrate real iterative debugging, the video is edited to compress lengthy generation and coding times.

Described by gemini-3.8-flash on 2026-09-29 from the video's audio and frames.