Quote:What is variable ATP?
Looking at a weapon in the item database that has a variable ATP, it will be listed as ATP: X-Y, X being the minimum possibility and Y being the maximum possibility. The calculated ATP will be somewhere between those two values. The game will calculate a variable ATP for each successful attack and add it to the character's base ATP. Just remember that the Y value will be what the game displays when it shows the combined statistic for a character's ATP.

Do grinders affect variable ATP?
Not really. When you grind a weapon it adds equally to both ends of the variable ATP, keeping the variance the same. Let’s assume a weapon has a default variable ATP of 50-100. If you grind that weapon to +5 (adding 10 ATP) your new variable ATP will be 60-110.

Does Shifta affect variable ATP?
Yes. When casting a level 30 Shifta, a weapon with a variable ATP will gain roughly 47% of the variable difference on the maximum (Y) value. Let’s assume a weapon has a default variable ATP of 50-100, which gives us a 50 ATP variance. If level 30 Shifta is cast on that character, this weapon will gain an ATP bonus equal to roughly 47% of 50, or roughly a 23 ATP bonus. However, this bonus is only added to the maximum (Y) value of variable ATP. And thus our 50-100 variable ATP weapon will now do 50-123 variable ATP. I also assume this works in reverse with Jellen by reducing the maximum (Y) value, but not changing the minimum (X) value. However, I have not fully tested that as of yet. Also remember that different levels of Shifta will have a different resulting bonus.

How about grinders and Shifta combined?
Grinders raise the variable ATP equally so that the variance between the minimum (X) and maximum (Y) values never changes. Therefore, the Shifta bonus will remain the same regardless of grinders.

Why does only the maximum (Y) value get a bonus?
I think this is done for a few reasons. First, a weapon with a variable ATP is somewhat less reliable than a weapon with a fixed ATP. So for that reason the weapon gains on its maximum to recover a little from being less reliable by being given the chance to do more damage. However, because it gets stronger from this Shifta bonus it also becomes even less reliable by getting an even wilder variable ATP.

So is there a way to figure out a decent (average) effectiveness of a weapon with variable ATP?
Yes. You can calculate a median (middle) ATP that would be an average scenario of what the variable ATP will calculate. To do this, find the difference in the Variable ATP. Using our example of 50-100, the difference is 50 ATP. Now divide that difference by 2. For our example 50 divided by 2 equals 25. Now take that value and subtract it from the maximum value to find the median. For our example 100 minus 25 equals 75. So granted an average scenario our variable ATP weapon will average 75 ATP. Remember to calculate Shifta bonuses separately.

So why do variable ATP in the first place?
For a little variety, I suppose. If you'll remember in the quest Value of Money you have to teach Garon that a weapon is more than just its outer appearance. You have to pay attention to its attributes. Variable ATP is just one more attribute that needs to be looked over carefully. Some weapons (like the Meteor Cudgel and Red Sword) aren't as reliable as they first appear. They have very high variable ATP scores and will do extremely wild damage. My only complaint is that ST didn't put any info about variable ATP in the game. The only way to truly know about it is from official Sega/ST publications, which I believe is where PSOW got the information (don't quote me on that).

How about a useful comparison example?
Sure. Let’s use the Meteor Cudgel and Demolition Comet, since most people seem to think the Meteor Cudgel is the better of the two statistic wise.

Meteor Cudgel has 300-560 base variable ATP, grinds to +15, and has a maximum variable ATP of 330-590. The variable difference is 260 ATP, and with level 30 Shifta it will gain a maximum bonus of roughly 122 ATP (bringing the variable ATP to 330-712, a difference of 382).

Demolition Comet has 530 base fixed ATP, grinds to +25, and has a maximum fixed ATP of 580. Since the ATP is fixed, there is no variance or Shifta bonus.

Without Shifta the Demolition Comet seems the overall better choice, as it will always give 580 ATP as opposed to the Meteor Cudgel having 330-590 with a median of 460.

With Shifta the issue gets a bit more convoluted. Level 30 Shifta bumps the Meteor Cudgel's maximum ATP to a whopping 712, but you also have to consider that the minimum is still 330. This means that the variance is now 382 and the median is 521. The Demolition Comet remains at 580, and therefore would still be the overall better weapon in a truly average scenario.

This truly puts a new perspective on things. Weapons that first appear to be really strong may not be as effective as one thinks. You truly do have to examine a weapon's attributes to understand how it will work in the long run.

Anyway, that about covers it. You can look over weapons to check for variable ATP here: http://romain.bernardi.free.fr/pso/classification.rar