Most players looking for a "ROM" specifically usually want to play . This is a fan-made port that loads the original game data but runs it in widescreen, with 60FPS special stages, mod support, and time attack modes. -backroomcastingcouch- Kate - Backroom Casting ... Direct
This guide covers how to officially obtain the game on Steam and, more commonly, how fans play the "definitive" version of the game today. The official, licensed method. Elitepain Dr Lomp Hot - 3.79.94.248
If you purchased Sonic Origins or Sonic Mega Collection on Steam, you likely noticed that "Sonic 3 & Knuckles" is not available as a standalone ROM file. Modern Steam releases often use encrypted archives or emulation wrappers that hide the game files.
To use this legally, you must provide your own ROM. If you own the game physically, you can dump it. If you own Sonic Origins on Steam, you can use a tool to extract the ROM data.