Keep it, but rename it. I suggest Sonic 3 & Knuckles (Merged) [Lock-On Simulation].bin . It is a historical artifact of how we had to play this game for nearly a decade. It’s a clever hack that solved a hardware limitation with brute force.
The speedrunning community has strict rules. Most runners use the original lock-on via a flash cart (like the Mega EverDrive). However, for practice and TAS (Tool-Assisted Speedrun) creation, the sonicknuckleswsonic3.bin file is preferred because it loads instantly and supports savestates. sonicknuckleswsonic3bin game file
In 1994, Sega released Sonic & Knuckles with a unique "Lock-On" cartridge. By physically plugging the Sonic 3 cartridge into the top of Sonic & Knuckles , players merged the two games into one massive adventure. Keep it, but rename it
: To stay within legal boundaries, players should create their own digital backups from physical cartridges they own using hardware like a Retrode. It’s a clever hack that solved a hardware
The Sonic_Knuckles_wSonic3.bin file is highly sought after today because it serves as the essential "legal base" for fan-made projects.
Whether you are revisiting Hydrocity Zone for the music or attempting a Knuckles-only speedrun, this file remains one of the most downloaded—and most debated—pieces of Sega Genesis history. Tread carefully, play honestly, and always keep a backup of your save file. The carnival night zone won't clear itself.