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Phantasy Star IV Item drops and rate

PostPosted: Mon Nov 06, 2017 2:00 pm
by lorenzo
I finished making the list for item drops and their rate for every enemy. If you come across an item that's not in the list, let me know.

I will also repeat what I said in other posts so everything is in one place: item drops are part of the enemy formation data, not enemy data. Enemy formations are compressed in ROM so it's not possible to edit them directly. The compression algorithm is Kosinski so you need to find a decompression tool for that and then edit the data and re-compressed the data in ROM. Alternatively I'm planning on storing the decompressed data in ROM so it's possible to edit them in the disassembly, however I don't know when I'll start working on it.

Here's the list:

Monster Fly: Antidote, 6.25%
Flatter Plant: Antidote, 18.75%
Toad Stool: Cure Paral, 12.5%
Gicefalgue: Antidote, 12.5%
Guilgenova: Antidote, 12.5%
Ismounos: Monomate, 12.5%
Speard: Ceramic Knife, 6.25%*
Tech User: Wood Cane, 6.25%*
Shadow Saber: Shadow Blade, 6.25%
Slave: Repair Kit, 12.5%
Float Mine: Dynamite, 6.25%
Zio's Guard: Dimate, 12.5%**
Tech Master: Force Cane, 3.125%**
Blauzen: Laser Claw, 6.25%
Greneris: Star Dew, 6.25%
Tower: Dynamite, 6.25%
Command Ball: Dynamite, 6.25%
Siren386: Plasma Dagger, 6.25%
Debugger: Repair Kit, 12.5%
Silvalt: Plasma Claw, 6.25%
Servant: Repair Kit, 12.5%
Frost Saber: Trimate, 12.5%
Chaos Sorcerer: Moon Dew, 6.25%
Radhin: Trimate, 12.5%
King Saber: Genocy Claw, 6.25%
Browren486: Repair Kit, 6.25%
Dominator: Sonic Buster, 6.25%
Shrieker: Cure Paral, 6.25%
Blood Saber: Trimate, 6.25%***
Dark Witch: Laco Rod, 3.125%***
Illusionist: Star Dew, 6.25%
Imagio Mage: Sol Dew, 6.25%****
Dark Rider: Moon Slasher, 6.25%****
Chaos Bringer: Defeat Axe, 6.25%



* When Speard and Tech User are in the same formation, Ceramic Knife will be dropped.
** When Zio's Guard and Tech Master are in the same formation, Dimate will be dropped.
*** When Blood Saber and Dark Witch are in the same formation, Trimate will be dropped.
**** When Imagio Mage and Dark Rider are in the same formation, Sol Dew will be dropped.

Re: Phantasy Star IV Item drops and rate

PostPosted: Mon Nov 06, 2017 2:37 pm
by Zucca
lorenzo wrote:Flatter Plant: Antidote, 1/5
That would result in item drop "value" of 25.6. Seems odd?
Did you meant 1/4? That would give value of 32.

Re: Phantasy Star IV Item drops and rate

PostPosted: Mon Nov 06, 2017 2:55 pm
by etony33
Awesome! Thank you so much.

Re: Phantasy Star IV Item drops and rate

PostPosted: Mon Nov 06, 2017 3:18 pm
by lorenzo
Zucca wrote:
lorenzo wrote:Flatter Plant: Antidote, 1/5
That would result in item drop "value" of 25.6. Seems odd?
Did you meant 1/4? That would give value of 32.


1/5 was an approximation....the drop rate is 24/128, which would become 3/16 but it reads odd to me, but I'm not sure. I'll edit the first post to use percentages. it'll probably be clearer

Re: Phantasy Star IV Item drops and rate

PostPosted: Mon Nov 06, 2017 3:27 pm
by Zucca
lorenzo wrote:the drop rate is 24/128, which would become 3/16 but it reads odd to me
3/16 == 1/(5+1/3) == 18.75% ... I guess.
lorenzo wrote:I'll edit the first post to use percentages. it'll probably be clearer

Yeah. Percentages could be the best way to represent the values.

Re: Phantasy Star IV Item drops and rate

PostPosted: Tue Nov 14, 2017 7:18 pm
by etony33
Hmmm. I just thought of something.

Can the quasi boss Chaos Sorcerer also drop a Moon Dew? I know that some enemies (Fract Ooze comes to mind) have two entirely different forms (with the Fract Ooze under Monsen being immune to ID attacks and having more HP), but I don't think that is the case with the Chaos Sorcerer. I can confirm that the saboteur Chaos Sorcerer is vulnerable to Holyword and Diem.

Re: Phantasy Star IV Item drops and rate

PostPosted: Wed Nov 15, 2017 9:48 am
by lorenzo
Nope, that Chaos Sorcerer does not drop a Moon Dew.

Re: Phantasy Star IV Item drops and rate

PostPosted: Thu Nov 16, 2017 1:19 am
by etony33
The data for the battle formations themselves (and the areas they can appear, as well as the rate at which they appear in a specific area) is not easily accessible, correct?

Re: Phantasy Star IV Item drops and rate

PostPosted: Thu Nov 16, 2017 6:17 am
by Zucca
etony33 wrote:The data for the battle formations themselves (and the areas they can appear, as well as the rate at which they appear in a specific area) is not easily accessible, correct?
That data is compressed.

I saw source code for the compressor somewhere... I'm not sure if it could also decompress.

Re: Phantasy Star IV Item drops and rate

PostPosted: Fri Nov 14, 2025 2:14 pm
by Gav the Monster
Fun fact:

Shadow Blade, Dynamite, and Defeat Axe and are the only three items in the game that can only be found from enemy drops.