So I'm going to go out on a limb here and assume that CF only uses RNG instead of PRNG. If this is wrong, feel free to ignore everything I'm about to say and call me stupid.

Going to be pretty lay man with this cause I'm not a math person so bear with me.

Random Number Generator skills are those with a % chance to do *something*. This could be something like Incarnadine Wave attacks with a % chance to do the -dex hit. Making up a number, lets say 20% of the hits you make are incarnadine hits. So roll a number 1-5, if its a 5, you get an incarnadine hit. This means each hit gets a 1-5 roll, and every chance is just as likely to be incarnadine as the last one. This leads to occasions of supreme luck where 10 hits in a row are incarnadine, and times of bad luck where 10 hits in a row give you squat.

The way Pseudo Random Number Generator skills work is that it tries to remove these instances of crazy luck and crazy bad luck which feel icky (or amazing) on either side. The system uses, instead of a 1-5 (we'll call it 1-100 with an 80 or above being incarnadine) roll on each of my attacks to see if they're incarnadine, a 1-100 roll where the first attack is maybe 5% chance of incarnadine, then 10% chance on the next attack, then 15%, and so forth, up to 100%, until an incarnadine attack is made. Then it would reset back to a 5% chance, and build from there. This means that the overall % chance of incarnadine is still 20%, but it makes horrible steaks of good or bad luck way less likely.

This is used in most E-Sports games, since it makes sheer luck slightly less valuable.

And yes, I used incarnadine instead of that other skill which I feel desperately needs PRNG.