So I'm guessing that applies to all moves that are documented as "having an accuracy"? That would include everything except Swift, Bide, Transform, and non-targeting moves. Thanks! My second question was that Growl supposedly has "100%" (255/256) accuracy, which means that it should work 99.6% of the time. However, when I've personally seen it used in the opening Rival battle (on a physical Red cartridge), it appears to display "But it failed!" a lot more often than 0.4%. Why?
No, that displays the message "Nothing happened!" in RBY. Look at any R/B TAS to see what I'm talking about: the Rival uses a stat-lowering move several times in a row, and they all fail. I'm pretty sure those are not all 1/256 misses.
I just tried it myself, no tools, on a Red ROM. I restarted the first Rival battle over and over, keeping track of each time the opponent used a stat-lowering move (Growl or Tail Whip). Out of a few dozen battles, the move almost always failed at least once per battle, which is something like a 15% or so chance. I'm a little suspicious that the fail rate is only 1/256.
The run also generates a miss for an attack which was not intended to be able to miss: Lt. Surge's Raichu using Thunderbolt in Vermillion Gym. Previously, I had listed this as luck manipulation, but after examining the disassembled code, I am also convinced that this is a programming error. Each attack has a miss ratio associated with it, which is simply stored as a value between 0 and 255. Attacks which are not intended to be able to miss have a miss ratio of zero. When determining if an attack has failed, a pseudo-random number is choosen, also between 0 and 255, and this value is subtracted from the miss ratio. If there was not a carry (if this value is less than or equal to the miss ratio), the attack will fail. Obviously, the programmer had intended to have these operands switched, and to check for carry instead; in the check for non-physical attacks, this is implemented correctly. This glitch was fixed in later generations of Pokémon.
The only exception is Swift which does not perform this check and, thus, cannot possibly miss.
Here is Pokemon Blue (J) "glitchless" in 1:31:06 by aruka. It was posted on Nicovideo about 5 months ago. The video is full of author comments. I have uploaded to Youtube with translation subtitles.
How do I hack the rom? Would this take a long time? And I didn't know I would need a new code for every single pokemon, I thought all of them give consistent experience points depending on their level or if they're wild/trainer's pokemon?
