Topic: FF4A (E) Hacking Notes and Mod

[Grimoire LD]

Hmm, that is strange...  so the table itself now decides the chance to drop, rather than the drop byte assigned to monsters in default FFIV? Also they all have their own unique AI Indexes? But to my knowledge no enemy really deviates from its basic AI index as laid down in the original FFIV, right? (except for new enemies, of course)

The overall AI of monsters is the same (as far as I know), but the AI codes themselves are different; there's a code for a generalized status check for instance:

Code: [Select]

$B1 TT CCCC PPPP
-If has any bits set within CC CC of type TT, move to point PPPP in AI script
-Usually used for Confusion routines (enemies use normal battle scripts to act when Confused)
-Also used for Egged monsters - Egg status does not automatically set script
Values for TT:
-0x0: Check normal status
-0x1: Check special status (Barrier,Boss,Reflect,etc)
-0x2: Check turn status bits (was attacked, immune to damage)

Ah hah... so they fixed some of the glaring inefficiencies of the original AI system which never actually looks for "was attacked" but instead looks to see what command was used. I can see how this one was at once simplified, and expanded. Well at least TOSE did something right there.

[Kea]

It's worth noting that the B1 conditional isn't generally used to check if a monster was damaged; usually B6 is used:

Code: [Select]

$B6 XXXX YYYY
-Checks +$44 in the monster's battle data; ANDS with XXXX
-0x0001 = hit by Attack
-0x0002 = Hit by Magic (black?)
-0x0040 = Hit by Jump?
-0x004F = Hit by anything
-0x0100 = HP damage?
-If check passes, move to YYYY in script
In related news, I had thought I'd cleared up every limit on text indices, but when I tested chests this happened:


Turns out that at the start of the text pointer table, there's a halfword which defines the maximum text index; indexes past that don't read end codes properly when used in dialogue, leading to what you see above. But now I've fixed it, and can do things like this:

Gotta say, it's a good feeling to finally have this working perfectly.

[Grimoire LD]

I like the look of that! Higher HP Zombie (attack probably a little too low) New item with the Ghoul Ring, all in all this looks pretty grand! Way to actually use the new space that FF4A had!

[Kea]

18x2 Attack is a little low, but Zombies have Dark-element physicals now, so Cecil ends up taking between 20-60 damage from each one. I also adjusted the Back Row modifier: instead of doubling defence, it halves the attacker's Attack Multiplier (to a minimum of 1), so the mages take about 20-32 damage even in the back row. I guess it couldn't hurt to bump it up a bit. Basic zombies aren't really supposed to be offensive threats anyway, the later types will be much nastier.

Now that I've changed the back row mechanics and added the new items I have everything up to Octomammoth done; Octo himself has a new AI routine designed to make him a threat for the entire course of his fight instead of being a pushover once you hit him a few times. I might release a test patch if there's interest.

[Grimoire LD]

I think there would be some interest. This is the EU version that fixed the glaring ATB bug, right?

[Kea]

It is, yes. I can't think of any reason to use the 1.0 version, given the option.

If you want to give it a try, here's a UPS patch and readme. Give me your thoughts if you give it a try!

[Kea]

I've updated the notes download in the first post; it includes more info on stat calculation, status magic, and level calculations. One interesting thing is randomized levels; the level at which to start using random levelups is defined by a single byte. You could have everybody use random levels from the moment they join if you wanted.

Poison status is a bit of a joke in FF4...it takes an age for it to do anything, and even if it didn't everything you might want to use it on is immune to it anyway. It's more notable for being able to block other statuses than for anything it does on its own. So I'm changing the formula that determines how much time passes between Poison damage hits. The old formula was this:

Code: [Select]

min( [(A+20)*Agl factor]/16 ),255Where A is Agility for players, and (Level+10) for monsters. The poison timer for a monster, assuming its Agility factor is normal, is at least 20 and as many as 119 ticks. Since bosses start at Level 10 and only go up from there, poison status is pretty useless against them. The new formula is this:

Code: [Select]

[(A/4)+15]*Agl factor/16With this formula the Poison timer is between 17-42 ticks for monsters, and 15-39 ticks for players. Much more useful, and much more deadly when used against you.

The poison spell itself will be useful beyond setting the status, as well - it's Dark-elemental now, and a little more powerful than the basic Fire/Ice/Lightning magic, at the cost of being more MP-intensive and inaccurate.

I'm also toying with something a little more ambitious: making Agility static for all characters. All characters, with some exceptions (eg Tellah, Rydia's first levels), would never increase Agility on level up, though their speed relative to each other would be the same as normal. The only way to modify a character's Agility would be through equipment choices -  Agility-modifying equipment would be more common of course. This would mean that gaining levels wouldn't help you outspeed a boss, and their Agility scores could be more finely tuned. It could be an interesting twist on the usual mechanics.

Since some damage formulas rely on Agility, they'd have to be changed to account for it being a static stat starting in the 30-70s range. Attack Multipliers might be calculated like this:

Atk M = 1 + (Str*Agl)/256

Which gives a very similar progression as the original game; Cecil gains his third multiplier at Level 15-17 under both systems.

[Grimoire LD]

Ah! You found what Avalanche had discovered for SNES FFIV and what I completely recorded. Yes FFIV uses the seemingly exact system. I fixed it by making it the same timer as Gradual Petrification, which as I recall was removed (the gradually petrifying portion) in versions past the SNES version, anyhow. I like the changes to Poison, PinkPuff did a similar thing in Unprecedented Crisis and I guess the idea came from FFVI and FFT where Poison spells are also normally what would be considered Dark Elemental.

You're telling me that they simplified the Random Levelup condition into a Single Byte?! That is infuriating! FFIV SNES jumps through several hoops and I still don't fully understand it! Does FF4A have a better Level up system all around? As in no more TNL and all of that bizarre activity?

So I've started to play your mod and I've noticed one glitch so far, when you go to save the game, the game shows what looks to be some programming comment in the overwrite warning message. This may be an emulator matter though and it's not impactful or anything anyhow.

It would appear as if SwordRats were buffed significantly having more than 40 HP and necessitating a Jump to defeat them without a punishing counter.

Steel Quill, eh? Now I might have to grind for that since it's just an uncommon drop. Haha, how lucky you are to have all of this space!

Oh, the Dark Sword can Blind now, quite nice!

Wow. HellDivers do Not play around! That was Combat Boost level of damage there, haha!

I must say I do appreciate your changes to the backrow. Instead of every attack being a "Miss!" It's now reduced damage, which feels much more appropriate!

I do not know what TOSE were on when they made the formations in this... every one so far defaults to the middle of the line, instead of the front!

What you have in mind for Agility is very ambitious and I would be curious to see how that ends up!

Well, still grinding for that Quill Blade, but its good to see that I take a few knicks here and there instead of 1 to 10 damage from every attack from anything for the vast majority of the start of the game.

[Kea]

You're telling me that they simplified the Random Levelup condition into a Single Byte?! That is infuriating! FFIV SNES jumps through several hoops and I still don't fully understand it! Does FF4A have a better Level up system all around? As in no more TNL and all of that bizarre activity?

It's still got 16 bytes for every level a character can reach, but there's no such thing as TNL; each level in the ROM is defined by the total amount of experience needed to reach it, and a character's current EXP is stored in RAM as their absolute amount.

Glad to hear you're enjoying the mod! That's a strange glitch with the save menu...probably an arcane result of the text table repointing. I'll make sure to fix that.

Don't be too fussed about the Steel Quill; it's a good non-elemental weapon but doesn't outclass the Shadow Blade, and Gatlingers will have much better chances of dropping it when I edit their data. The general pattern for most rare drops is that they'll be available as a very rare drop before the area they're tuned towards, and then some time later as a rare or uncommon drop, or as a treasure. Some of them will just be hard to find, though!

I wanted to make the early enemies at least potentially dangerous; Helldivers won't wipe you if you know what they're doing, but they're a worthy foe now. Sword Rats are the same idea; they're there to make the early portion of the game a bit more thoughtful than hitting Attack.

The Dark Sword change lends some utility to Cecil, since he was otherwise pretty straightforward in how he was used. Dark Knights being adept at debilitating their opponents also helps contrast the class with the Paladin.

[Grimoire LD]

It's still got 16 bytes for every level a character can reach, but there's no such thing as TNL; each level in the ROM is defined by the total amount of experience needed to reach it, and a character's current EXP is stored in RAM as their absolute amount.

Glad to hear you're enjoying the mod! That's a strange glitch with the save menu...probably an arcane result of the text table repointing. I'll make sure to fix that.

Don't be too fussed about the Steel Quill; it's a good non-elemental weapon but doesn't outclass the Shadow Blade, and Gatlingers will have much better chances of dropping it when I edit their data. The general pattern for most rare drops is that they'll be available as a very rare drop before the area they're tuned towards, and then some time later as a rare or uncommon drop, or as a treasure. Some of them will just be hard to find, though!

I wanted to make the early enemies at least potentially dangerous; Helldivers won't wipe you if you know what they're doing, but they're a worthy foe now. Sword Rats are the same idea; they're there to make the early portion of the game a bit more thoughtful than hitting Attack.

The Dark Sword change lends some utility to Cecil, since he was otherwise pretty straightforward in how he was used. Dark Knights being adept at debilitating their opponents also helps contrast the class with the Paladin.

Bah, if only we could break this TNL garbage for FFIV SNES, since it seems they just found a way to ignore it all together for FF4A.

Ah? I had assumed that because it was second on the list it was the SwordRat's uncommon drop? Is that not the case then? Good to know Gatlingers will have a better chance to drop it. I did pick up a Goblin Summon through all of that grinding though so I guess it wasn't a complete waste of time.

The Mist Dragon at least dealt damage, not sure about its speed though, granted I was Level 15 due to all of the grinding though. I also like how you have Titan outright kill Cecil and Kain, I mean, it makes sense instead of the 70-80 it deals in other versions.

Aside from being slightly faster the Soldiers and General did not seem much more powerful.

Hmm, Goblin Punch still seems useless and SandWorms still deal only 5 or so damage with Cyclone (because it's tied to their Max HP, if I recall right)

Did you increase the power of the Rod's magic attack or did this version do so? It dealt 60 damage to a normal foe!

Umm... Desert Sahagins have 4 Attack... I cannot assume that was the intention. Hundlegs only have 11 at that measure... this does go up to OctoMammoth, right?

Killer Fish have disappointing Attack stats as well only dealing 5 or so damage to a Level 5 Rydia.

Everything here seems to have 11 Attack which is normal as far as FFIV is concerned but that x2 multiplier for them does not appear to be cutting it.

I like the chance of a Polymorph Rod from the Gigantoads, nice touch!

Alright! Now that's a nice change of pace. The Toadgre's can cast Blizzara which is high damage for this point, but survivable and Toad (which they did cast originally anyhow) can be quite deadly. Well conceived.

Toadgre's I feel have the appropriate strength, if not a little less strength than this area should provide. I wonder if that Lilith's Kiss is a 1/8 item or much lower...

For 2 MP Poison deals a pretty good amount of damage!

Ah, Zombies poison, very nice. Did you also include your ffaster Poison? Since I noticed that Rydia actually took a measure of Poison damage during the fight. I like their boosted stats as well.

Was not expecting Silence from Flans... do you sell Echo Herbs at early shops then? Since in the normal game they aren't available until Mysidia as I recall.

Alligators are more than respectable foes with 48 Attack but I imagine that they probably have lowish Accuracy.

Seems like Mini-Mage's are still a bit tricky.

Ah, the dummied Hand Axe, an interesting place to put it.

Only the Hades Armor here? Interesting...

The Hand Axe is a legitimate thrown weapon, nice touch. Though I'm not sure giving the Dark Knight even more survivability with background usability as being such a great idea. I guess I'll see.

Did they change the way Magic Items worked in FF4A?  I noticed that Tellah seems to be dealing more damage with the Rod than Rydia was doing.

And Octomammoth is down! I like what you did here. As you fight him his attack mulitpliers increase. At the start I used Tellah for Blink on Rydia mostly so she can hammer away at him with Chocobo and while he started to deal more and more damage we were able to keep pace and defeat him. A very satisfying boss.

All in all this is a promising start and I have to give TOSE credit where credit is due, FF4A does feel much faster and more fluid than its SNES counterpart, giving it a more frantic feel which is missing from the SNES version.

[Kea]

Ah? I had assumed that because it was second on the list it was the SwordRat's uncommon drop? Is that not the case then? Good to know Gatlingers will have a better chance to drop it. I did pick up a Goblin Summon through all of that grinding though so I guess it wasn't a complete waste of time.

Did you increase the power of the Rod's magic attack or did this version do so? It dealt 60 damage to a normal foe!

The ingame bestiary in this version condenses multiple drops of the same item into one entry; the Sword Rat's actual drop list is Gold Needle x3/Steel Quill. That is a little confusing, so I might try to remove that behaviour.

The Rod's magic works a little differently than in vanilla; the spell it casts has only 3 base power, but the Rod itself has a very high fixed multiplier, so it's supposed to be good against enemies with low magic defence. That said, it seems like FF4a multiplies a spell's power by 4 before subtracting Magic Defence, so it might be a bit overtuned; I'll reduce it to 2 (8) base power.

Everything here seems to have 11 Attack which is normal as far as FFIV is concerned but that x2 multiplier for them does not appear to be cutting it.

I like the chance of a Polymorph Rod from the Gigantoads, nice touch!

Alright! Now that's a nice change of pace. The Toadgre's can cast Blizzara which is high damage for this point, but survivable and Toad (which they did cast originally anyhow) can be quite deadly. Well conceived.

Toadgre's I feel have the appropriate strength, if not a little less strength than this area should provide. I wonder if that Lilith's Kiss is a 1/8 item or much lower...

I could have sworn I increased everything's Attack in the desert and Underground Waterway. I must have missed it then; they will definitely become more threatening than they used to be. Toadgres could maybe use some more attack so that they're more of a threat earlier in their fights - they only use Blizzara when they're alone currently.

The faster Poison status isn't in yet (nor is the more expensive Poison spell). Echo Herbs aren't sold in shops yet which is an oversight on my part; I'll add some Echo Herbs to Kaipo's shop in the next version.

The Hand Axe is a legitimate thrown weapon, nice touch. Though I'm not sure giving the Dark Knight even more survivability with background usability as being such a great idea. I guess I'll see.

Did they change the way Magic Items worked in FF4A?  I noticed that Tellah seems to be dealing more damage with the Rod than Rydia was doing.

The Hand Axe reduces your Agility by 3 and only has 70% accuracy. The concept for the Hand Axe was that you'd only use it when the Shadow Blade couldn't do anything or when staying in the front row was too dangerous for Cecil. Maybe the current penalties aren't enough of a tradeoff, though...

Spells cast from items still have a fixed spell multiplier. It was probably just random variance, some monsters have Magic Evade now.

[Kea]

I'd finished everything up until Antlion but had a hard time thinking of a good script for him...now I've got a good idea.

I've created a new AI command that lets a monster pick between one of three spells (+basic physical) randomly:

Code: [Select]

@New AI command that randomly selects one of three spells, then casts it
@Exceptions are IDs 0xC0 and 0xC1, which are linked to the two types of physical attacks instead
.thumb
push {r4,r5,r14}
mov r4,r0
mov r5,r1 @r5 = command parameter offset
mov r0,#0x3 @Picking one of three commands
ldr r2,RandomNum        @Generates a random number between 0 and 2
bl Longcall
ldrb r1,[r5,r0] @Loading spell ID to use
cmp r1,#0xC0 @(spell IDs 0xC0 and 0xC1 are for Red and White Fangs - no loss)
bne Physical_2_check
ldr r2,Physical_1
b Branch
Physical_2_check:
cmp r1,#0xC1
bne Spell
ldr r2,Physical_2
b Branch
Spell:
ldr r2,SpellCast
Branch:
bl Longcall
cmp r0,#0x0
beq Jump_false @Proceed to the next command
Jump_true:
mov r0,#0x0
strb r0,[r4,#0x19] @Not a consecutive command
b Store_jump_bit
Jump_false:
strb r0,[r4,#0x19] @The spell cast has already specified where to go next
mov r0,#0x1
Store_jump_bit:
strb r0,[r4,#0x1A]
pop {r4,r5}
pop {r0}
bx r0

.align 2
RandomNum:
.long 0x0805AF55
SpellCast:
.long 0x080863DD
Physical_1:
.long 0x0808642D
Physical_2:
.long 0x08086409
Longcall:
bx r2

These two things might be related. 

[Grimoire LD]

The ingame bestiary in this version condenses multiple drops of the same item into one entry; the Sword Rat's actual drop list is Gold Needle x3/Steel Quill. That is a little confusing, so I might try to remove that behaviour.

Might not be a bad idea, I can see why they did it, but it is very misleading.

The Rod's magic works a little differently than in vanilla; the spell it casts has only 3 base power, but the Rod itself has a very high fixed multiplier, so it's supposed to be good against enemies with low magic defence. That said, it seems like FF4a multiplies a spell's power by 4 before subtracting Magic Defence, so it might be a bit overtuned; I'll reduce it to 2 (8) base power.

Multiplies a Spell's Power by 4? Hmm... I wonder how that differs from the original? I know there is something similar that happens there as I recall.

I could have sworn I increased everything's Attack in the desert and Underground Waterway. I must have missed it then; they will definitely become more threatening than they used to be. Toadgres could maybe use some more attack so that they're more of a threat earlier in their fights - they only use Blizzara when they're alone currently.

The faster Poison status isn't in yet (nor is the more expensive Poison spell). Echo Herbs aren't sold in shops yet which is an oversight on my part; I'll add some Echo Herbs to Kaipo's shop in the next version.

Well I do have a savestate right before Mist, so I could run through again, eventually. Ah, so the new
poison isn't implemented yet.

The Hand Axe reduces your Agility by 3 and only has 70% accuracy. The concept for the Hand Axe was that you'd only use it when the Shadow Blade couldn't do anything or when staying in the front row was too dangerous for Cecil. Maybe the current penalties aren't enough of a tradeoff, though...

Spells cast from items still have a fixed spell multiplier. It was probably just random variance, some monsters have Magic Evade now.

Right, Magic Evade is important, to keep in mind. I suppose it was just randomness. I think the -3 Agility is a good idea, but in reality I didn't notice too much of a difference in attack between the two.

I'd finished everything up until Antlion but had a hard time thinking of a good script for him...now I've got a good idea.

I've created a new AI command that lets a monster pick between one of three spells (+basic physical) randomly:

Code: [Select]

@New AI command that randomly selects one of three spells, then casts it
@Exceptions are IDs 0xC0 and 0xC1, which are linked to the two types of physical attacks instead
.thumb
push {r4,r5,r14}
mov r4,r0
mov r5,r1 @r5 = command parameter offset
mov r0,#0x3 @Picking one of three commands
ldr r2,RandomNum        @Generates a random number between 0 and 2
bl Longcall
ldrb r1,[r5,r0] @Loading spell ID to use
cmp r1,#0xC0 @(spell IDs 0xC0 and 0xC1 are for Red and White Fangs - no loss)
bne Physical_2_check
ldr r2,Physical_1
b Branch
Physical_2_check:
cmp r1,#0xC1
bne Spell
ldr r2,Physical_2
b Branch
Spell:
ldr r2,SpellCast
Branch:
bl Longcall
cmp r0,#0x0
beq Jump_false @Proceed to the next command
Jump_true:
mov r0,#0x0
strb r0,[r4,#0x19] @Not a consecutive command
b Store_jump_bit
Jump_false:
strb r0,[r4,#0x19] @The spell cast has already specified where to go next
mov r0,#0x1
Store_jump_bit:
strb r0,[r4,#0x1A]
pop {r4,r5}
pop {r0}
bx r0

.align 2
RandomNum:
.long 0x0805AF55
SpellCast:
.long 0x080863DD
Physical_1:
.long 0x0808642D
Physical_2:
.long 0x08086409
Longcall:
bx r2

These two things might be related. 

I actually hacked such a thing for default FFIV as well, tying it to an unused skill and giving most monsters four possible random actions to perform, even bosses. It did have limits though. It could only be single target.

But... then I got a bit crazy and worked myself into a corner with Job Classes and 90 new spells I put a lot of work on my plate and I couldn't actually complete that project. I could easily salvage the AI part, since it was meant to work in tandem with Chillyfeez's Enemy Leveling patch.

[Kea]

(bestiary talk)

Might not be a bad idea, I can see why they did it, but it is very misleading.

It's done; it turned out to be another one-byte fix. I also fixed the save menu text error - that one was a find/replace mistake from when I was formatting the game script for reinsertion.

Right, Magic Evade is important, to keep in mind. I suppose it was just randomness. I think the -3 Agility is a good idea, but in reality I didn't notice too much of a difference in attack between the two.

I might take the Hand Axe to -5 Agility, then. Lowering Agility will also indirectly reduce its damage later since you won't have 16 Agility for an additional attack multiplier; makes it not so powerful by Mt. Hobs. Of course I would appreciate it if you ran through the updated Kaipo/Waterway section, but feel like you're obliged to do it; ROM hacking is a hobby in the end after all.

I actually hacked such a thing for default FFIV as well, tying it to an unused skill and giving most monsters four possible random actions to perform, even bosses. It did have limits though. It could only be single target.

But... then I got a bit crazy and worked myself into a corner with Job Classes and 90 new spells I put a lot of work on my plate and I couldn't actually complete that project. I could easily salvage the AI part, since it was meant to work in tandem with Chillyfeez's Enemy Leveling patch.

Yeah, under my system all three possibilities must share the same targeting. I ought to make a variant of this command that has the monster pick between three spots in the script to jump to.

I've seen/played some of your Combat Boost mod, I thought it was quite good. The new character commands were especially impressive and fun to play around with. It's too bad you got burned out on it; I can sympathize with giving yourself too much to handle.

[Grimoire LD]

Oh no, Combat Boost is alive and well. That's been making progress here and there. (Just I want to finish the Underworld before release as I had finished the Overworld the first time before an official release). It was my side project which... sort of became the main project for a while and I did really think about combining Combat Boost with it at first, but then I realized how much of a headache that would have been so I thankfully abandoned that line of thought before anything of the sort. Good thing I didn't. Combat Boost keeps things at a manageable level for me.

I think -5 Agility is a much better compromise and I would be glad to play through the desert and the Old Waterway again with properly boosted foes though at the same time don't forget to make risk hold reward. You may want to boost Exp. from enemies at some points so the game feels balanced and doesn't require grinding off of trash forever to survive later encounters.