Lore found in The Great Gubal Library (Hard) [SPOILERS YO!]

[Shadotterdan]

Nah, they increased in damage if cast successively, the point being to have a bunch of BLMs cast the same one for massive damage.

[WhiteArchmage]

Koji Fox obviously didn't have faith in the playerbases intelligence if he thought they couldn't get their head around suffixes

Or he was planning ahead to when we reach Fire/Cure/Thunder/Whatever V/VI/VII and such. And FFII didn't have -ra, -ga, -ja either because the spell leveled up so you would go all the way to Fire XII (or XIV? I think XIV was the cap...). The localization has a lot of fanservice for the american audience, not those that think that if you didn't play it in the original japanese in the famicon means you're not a real fan.

[Zojha]

It used both.

And that IMO is the best way to go.

Fire II implies that it's a better version of Fire I. Same name, same spell, just new and improved! Fira implies that it's a different spell and has a different use, much like Cure and Medica.

I could imagine the thunder spells of a black mage to be numbered for example. It's pretty much the same spell, only difference is that it does more damage for more cast time. Fire I and Fire II however...are not much alike, they have vastly different usage.

[Yasuhiro]

The localization has a lot of fanservice for the american audience, not those that think that if you didn't play it in the original japanese in the famicon means you're not a real fan.

null argument because every FF re-release used the system we see today and him using the numbered system still doesn't make sense even if we go beyond -ja just name them as they are, tool tips and job quests exist.

[Yasminou]

It used both. Strength was measured in I-V, but -ga spells were AoE (and also tiered I-V.) So Thunder II and Thundaga II both existed. -ja spells existed too. I can't remember what they did, I think they were AoE and decreased in damage if you cast it successively.

-ga spells were aoe around the target (like Fire II in FFXIV), while -ra spells were aoe around the caster (like Blizzard II in FFXIV).
-ja spellls were like -ga with an increase in potency for successive casts, as you said: they were mosty introduced in order not to give -ga IV spells to BLM, as they would have been overpowered (mobs had had them for a long time with a casting time shorter than -ga III and a small mp cost).

On a side note, I need to rerun Gubal hard but if I recall correctly, in French, the message about Cure spells talks about Giga Soin, Ultra Soin and another name: the concil chose the name Giga Soin (since Fire IV / Blizzard IV are Giga Feu / Giga Glace in French).

[Belhi]

Does anyone actually know what Cure 4 does? I have never quite figured out what it does mechanically when Kuribu casts it. It certainly doesn't seem to heal for a lot.

[MilesSaintboroguh]

Does anyone actually know what Cure 4 does? I have never quite figured out what it does mechanically when Kuribu casts it. It certainly doesn't seem to heal for a lot.

It's linked to the pillars of light she summons, so each player standing on it weakens her healing potency. I had some occasions where people missed it, which caused her HP to be healed for more and gave her Regen.

[Morningstar1337]

Does anyone actually know what Cure 4 does? I have never quite figured out what it does mechanically when Kuribu casts it. It certainly doesn't seem to heal for a lot.

Its an AoE like III, however that fight usses it more like an offensive spell then a curative one. So wither the potency might change for players or it is meant to be used offensively with reverse (banking on the former though)

I shouls note that some spells work different when used by opponents Cure III was also affected by Reverse but was otherwise the same (it just have a telegraph like other player used actions that the enemy uses like Overpower) The Voidsent and Ixal in Xelphatol had their own versions of Fire, Blizzard and Aero spells and Sophia has er own version of Thunder II and II (which are a klarge cleave and a Lunal Dynamo attack rather than just being Thunder with an extension, though I wonder if there was meant to be a prefix attached like with the Void and Ixali spells)

[Fiaryn]

You mean a system that's always been in Final Fantasy since Japanese releases? The numbered system was only in FF1, II(IV) and III(VI) Because of space limitations and FFVII because that translation was mediocre. Ra/Ga/Ja is the proper naming convention for these spells even Record Keepers FFXIV events uses them. Koji Fox obviously didn't have faith in the playerbases intelligence if he thought they couldn't get their head around suffixes

"A system that has always been in place, except when it hasn't been. Truly an unforgivable crime against our timeless and unshakeable traditions"

To be more direct: It's pretty much a completely arbitrary value judgement either way.

[Yasuhiro]

"A system that has always been in place, except when it hasn't been.

Except it has. All re-releases of Final fantasy games have opted to use the ra/ga and ja system.