The first rule of ROM hacking seems to be, "You will refrain from assembly hacking." Some hackers never understand assembly language. Some hackers avoid assembly but use assembly in small amounts. Some other hackers use assembly somewhat frequently.

One of the users of SMWcentral asked the community of hackers of Super Mario World if assembly would be "fun".

• SMWcentral, Would you consider ASM Hacking... Fun?, 3 July 2009

The context of this thread has that these hackers use 65816 assembly language, because SMW is a SNES hack. Many of these hackers have never applied assembly language to anything other than SMW. Here are some quotes from the thread.

• Quizler: "Or maybe somebody gets a kick out of doing things with.. letters, numbers, and.. money signs? (seriously I don't get that)"
• Jirachi: "Certainly not, I remember nearly tearing my hair out over it.... If anyone here does actually enjoy ASM, I would concider you strange."
• Kyurel: "I think ASM is fun, but not extensive ASM. Maybe a block, or a simple patch."
• Ersanio: "I consider ASM hacking fun since it opens many doors to REAL ROMhacking."

From these four users, I guess that they are the user who treats assembly as a mystery, the user who dislikes assembly, the user who keeps a limit to assembly, and the user who feels the most potential with assembly. The first three users would hack ROM images without doing any extensive assembly hacking.

When you start with a base hack, you already have the machine code for an entire game. If you only replace the messages with translated messages, or replace the level data with new levels, or edit the palettes or the graphics, then your ROM hack needs no assembly code. By this way, you can escape the need to make a new game engine using assembly code.

This is not the manner of the first ROM hackers. For the SNES, I mean the ROM hackers who created the original licensed SNES games, which we use as our bases. In the case of Super Mario World, I mean Nintendo's own hackers, who drew the Mario graphics, composed the classic SMW music and designed the original levels; but who also programmed the world map and the game engine using assembly code. We, the ROM hackers of today, making SMW hacks, might avoid assembly, but the original ROM hackers of SMW did extensive assembly hacking.