Why is this so difficult to understand? If a character's attacks are doing 1000 damage before the DC is active, then this already includes Mothma's 90% reduction and Jabba's 30% reduction and whatever Krrsantan's defense is mitigating. So, now just take 75% off of the 1000 = 250. It really is that simple.
Let's look at armor shred for an example: each instance of armor shred reduces defense by 50%. So, a character with one armor shred is at 50% of their normal defense. The second armor shred does not reduce them to 0 defense. It takes 50% off of 50%, so they have 25% of their normal defense. The next AS reduces it to 12.5% of the normal defense. And so on.
Here's a second way of figuring the problem. Don't add the percentages off, multiply the remaining percentages. 90% off = 10% remaining (0.1). 75% off means 25% remaining (0.25). and 30% off means 70% remaining (0.7). Multiply 0.1 x 0.25 x 0.7 = 0.0175 or 1.75%. So, if an attack with no reductions would do 1,000 damage, then the attack after all of the percent reductions would do 17.5 damage. Yes, that is very low, but it is not 1 damage.
And it's not me "deciding for myself how the maths should work." There is a proper way these functions operate. I teach this to my students. CG has this one wrong. That is why it is a bug. It is programmed incorrectly.
It doesn't matter how you think it should work, just the way it does work. All stacking multipliers work that way in the game.
Actually you are wrong. Look at armor shred. The first one reduces defense by 50% of the character's max. The second one does not take them to 0%, it take 50% off of the 50% remaining. The third takes 50% off of the 25% remaining and so on. This is the correct way of calculating multiple percents off.
