Factors that affect drop rate?

Can you speculate about what could affect drop rate in the common cases?

I feel guilty buying scrolls. So, I have a rule that I will only use scrolls that I get from drops. Except that I break my rule sometimes, when the scroll isn't very expensive, or I'm tired of trying to get the scroll, or I don't want to try.

My level 89 RDM wants Blizzard IV. So, I killed 230 Doom Warlocks in Gustav Tunnel and never got Blizzard IV. I gave up today and bought it. But, I'd like to know theories about what affects drop rate.

A melee person told me once that using magic reduces drop rate. So, that has nagged at me and I find myself trying not to defeat the fiend with magic even though I doubt that affects the drop rate.

In Gustav Tunnel, I quickly got Billard III, Blizzaga II, Blizzaga III and Freeze. So, I kept those in my inventory, thinking that might somehow make it more likely that Blizzard IV would drop. Then I worried, maybe having them in my inventory reduces the drop rate...

Another thing I thought of is that maybe Doom Warlocks no long drop Blizzard IV. Or, a certain number of the scrolls drop each day, so the level 99 people get them all?

Or, being a level 89 RDM reduces the drop rate of a level 89 RDM scroll.

Speculations?

Only thing that effects drop rate is Treasure Hunter.

Everything else is baseless speculation, and almost entirely proven false. There has never been any evidence to any of the theories out there. The only one I could remotely believe is Moon Phase, simply due to personal experience, But thats also been mostly debunked and has little to no supporting evidence at all.

Now, However, Back in the day, Using -GA Spells to farm as /THF, all Enemies received Treasure Hunter. Now adays, As far as i know, Thats been nerfed, only the targeted enemy receives Treasure hunter, That might be where he got the "Magic" bit from. But no, Magic does not nerf drop rates.

So in closure, There is nothing at all, Except Treasure Hunter, proven to increase drop rate.

http://ffxidb.com/zones/212/doom-warlock

The drop rate is just really low. 1.6% means you can go a very long time without seeing it drop. And that probably includes quite a few TH kills, and TH1 essentially counts for two kills, TH2 for three. I wouldn't be surprised if the actual chance was below 1%.

Aside from that, what Karby said. Only TH is known to affect drops (and staggering mobs, if you happen to be in Abyssea, Dynamis or Voidwatch).

When I went after Tornado, it was right around 100 kills before it dropped. That was right around the 1% rate that ffxiencyclopedia had listed. For this attempt, it was 230 kills and no drop. So, that would mean less than .5%. That made me wonder if there could be some reason for that, other than randomness.

With low drop numbers the variance in average tries to get it increases, which is why a 1% drop rate will often result in significantly more than 100 kills needed.