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1

Scripting and Reverse Engineering / [FF7] Physical Hit% Calculation

« on: 2023-12-20 04:10:53 »

I was reading qhimm 20661 and gamefaq's battle mechanics guide and unless I'm doing something wrong they aren't correct in regards to physical hit% calculations on Ruby weapon.

So the claim is:
hit% = (Dex/4 + Atk%) + Def% - EnemyDef%

Where Def% is Dex/4+Armor Def% Value

Here's an example:
A Level 51 Cloud with 42 Dex equipped with an apocalpyse with 120 atk% and a mystile giving 50 def% Ribbon fighting Ruby Weapon with 100 Def%
(42/4+110)+(42/4+50)-100 = 81%

If you believe EnemyDef% uses Dex then:
(42/4+110)+(42/4+50)-(253/4+100) = 17.75%

However when I fight Ruby I only see 3-4 misses occur out of 64 from lucky 7777's giving a ~95% success.

Ruby has a terrible luck of 10 while Cloud has a luck of 24 so you can expect some misses to be critical's and lucky strikes, but this seems way off.
Lucky strikes should be luck/4 = 6% of the time
Criticals should be luck+level-elevel/4 = 4% of the time
I saw multiple critical so that can't be right...

Using Ultima Weapon instead of Apocalpyse, Cloud never misses.

Magic has also never missed.

Example #2
Red XIII Level 57 60 Dex 25 luck Plus Barrette 104atk% Mystile 50 Def% Ribbon
15+15+104+50-100 = 84%
15+15+104+50-163.25 = 20.75%
In game: 0-1 Misses

Swapping Mystile for Rune Armlet 5 Def%:
15+15+104+5-100 = 39%
15+15+104+5-163.25 = -24.25%
In Game: 23/64 Misses = 64%

It's not just lucky 7777 strikes either as doing individual attacks manually seems to follow the same luck as well.

Same results on PC and PSX.

2

Scripting and Reverse Engineering / [FF7] 3D Battler RNG

« on: 2022-11-11 04:11:29 »

I didn't see much online about the 3D Battler so I took a look at it.

https://gamefaqs.gamespot.com/boards/197341-final-fantasy-vii/54471793

Here's what I learned.

It does not matter what you pick, just when you pick it. It doesn't look at your input at all, whether you win or lose is based entirely on random.
However random is a single byte that increments at about 10-12 per second depending on your movement to the arena and is continually generated by movement of the background characters.
This random random value is at 095dc8 on PSX and FF7_EN.exe+8BF588 on PC
Damage is a counter that increments to 10 at 75e30/FF7_EN.exe+8C14DC (you) and 75e31/FF7_EN.exe+8C14DD (enemy)

Fighter 1: You have a 65.93% chance of winning
Fighter 2: You have a 51.17% chance of winning
Fighter 3: You have a 33.33% chance of winning
Fighter 4: You have a 25% chance of winning
Fighter 5: Is a ghost you cannot kill. Low is a Hit, but the value does not increment in memory. Mid is a Tie. High is a loss.

All considered and random being fair you have a 2.81% chance of getting to the ghost and winning 300gp.

I was thinking maybe it would be possible to find a starting seed that won with a turbo controller, but with how fast RNG increments, this would be very hard to get frame perfectly.
With a turbo controller this could likely be exploited by simply running the game for a while pressing O+X repeatedly as it won't stop until you run out of money or hit the ghost.
That said you are definitely better off doing chocobo races for GP, but it is nice knowing how this mechanic works.


Here are the charts for each fighter. Each seed value has a guaranteed result no matter what input you pick.
If you can see the random seed, you can use these charts to better time your inputs to increase your chances of success.

3

Scripting and Reverse Engineering / [FF7] Chocobo Betting

« on: 2022-01-20 22:27:42 »

Does anyone know how the winning chocobos in the gold saucer chocobo betting are calculated or where to look?

Fuzzfingergaming made a video describing his process: https://www.youtube.com/watch?v=jXLHLeT12Ts

I made an html tool to calculate the chocobos using his formula, but it's not perfect.

https://www.youtube.com/watch?v=0EPUW8ckGwg

I know if you use save states on the chocobo betting win pre game screen you can return after the race and re-input the values to get the same result. So the results should be pre calculated based on stats and jockey color.

Would be nice to know the official equation that calculates the winners. I'm not sure where to go looking to find this however.

Anyone able to help?

*Future Me Here* Fuzzfingers method is 63.38% accurate, which really isn't bad. I learned a lot about the game, but there's really just too many random number lookups happening to do better without manipulating RNG. Which I did eventually figure out how to do on both PSX and PC builds https://ff7man.github.io/rng.html