Do instant-kill moves in Phantasy Star IV work better or worse depending on the enemy type?

I've been playing PSIV - End of the Millenium, and I thought that "chance to instantly kill" moves were fairly worthless, up until I got to Nurvus.

At this point in the game, you have to regularly fight high-HP mechanical/robot enemies. Some of them, like... uh... Bulzaren? Or something? The one that has a ridiculous amount of defense and floats with rockets. Anyway, some of them are difficult to defeat with conventional means. So I began experimenting with the instant-kill moves some more.

One thing I began to notice is that Demi's Spark skill seems to consistently kill these robotic enemies. Out of about 15 uses against robots, only one of them failed.

Then it hit me: Duh, she's an android, so she uses an EMP (or maybe hacking) to disable other robots instantly, that's why Spark works so consistently. In game terms, they probably doubled the chance for the skill to work against robotic enemies.

To contrast, Gryz's Crash is very hit-and-miss across all the enemies I've tried it on, and Rika's Eliminate has literally never succeeded, ever.

So my question is this: Does it matter what kind of enemy I use the different instant-kill moves on, and do different moves work better against certain enemies?

EDIT: I should add that before I went to Nurvus, Spark seemed about as helpful as the other instant-kill moves (that is, not very)

1 Answer

Yes. All weapons and most techniques and skills are divided into one of 14 different attack categories. Each enemy has its sensitivity value, between 0 and 4, for each of these categories. Spark and EMP both lie in category 12, which is only effective (above 0) for mechanical enemies. Conversely, the Death ability won't work against mechanical enemies (sensitivity 0). Even within these creature types, the sensitivity varies from one creature to another, usually by 1 point (e.g. usually 2-3 for Spark et al.). Half the enemies in Nurvus are mechanical and have a sensitivity of 2 to Spark's category, which is why Spark is so effective there (that and Spark's high base effectiveness).

(Source. The explanation and table of attack types can be found under "Quantitative Analysis of Attacks". While the the list of monsters and their sensitivities is under "Monster Guide".)