The Jeweled Stud of Madness has the Ferocity II focus effect, which is supposed to increase double attack rate by 6%. Upon testing on both Aradune and Test, this focus has no benefit to either Beastlords or Bards who gain double attack as an AA. Nowhere in the effect description (or Alla, or Lucy) does it specifically call out that the double attack skill must be innate, leaving me quite frustrated to find that it did nothing for me as a Beastlord after winning this from Inktu`Ta. The stats are great - but the effect is really where this item is supposed to shine.
How exactly did you test it out? It works, the chance is just super low in that era so you're not going to notice a big difference unless you do some pretty long parsing, and even then the DPS gains are minimal. The math is: Double Attack Chance = (Skill + Level) * Mod / 500 BST doesn't have the skill, while Ferocity and the AA go in the mod spot for GoD: (0 + 65) * (1 + 0.06 + 0.30) / 500 which gives you only a 17.68% chance of even attempting a double attack. So without that Ferocity II, its (0 + 65) * (1 + 0.30) / 500 which is only 16.9% So Ferocity II increases your chance to double attack by <1%. You're not going to notice that unless you do some super-long parses. It works, it's just tiny. Notabug.
I tested this yesterday. Facts: Ferocity worn effect does nothing without having Burst of Power. It does nothing if you don't already have double attack. This is called out, but I've seen forum posts mention it gives double attack, it doesn't. With Burst of Power 5, you have a 15% chance to double attack. You can see this by plugging it into the equation above for double attack Double Attack Chance = (Skill + Level) * Mod / 500 Double Attack Chance = (0+65) * 1.15 / 500 Double Attack Chance = 74.75 / 500 Double Attack Chance = 14.95% With Double Attack AA which they round up to 15% in the description of the ability. Use the same formula but adding Fero (2 or 3, i tested with 3, but its 3% per rank) Double Attack Chance = (Skill + Level) * Mod / 500 Double Attack Chance = (0+65) * 1.23 / 500 (Fero 3) Double Attack Chance = 79.95 / 500 Double Attack Chance = 15.99% With Double Attack AA So we see a 1% increase, and it is noticeable with the Fero effect. I was seeing around 2 more double attacks per minute with my limited data testing, so it is definitely a DPS increase, but it isn't a straight 9% increased chance to double attack, it follows the formula just like everything else I'm posting this because there just doesn't seem like a lot of actual data on this issue available.
We can add more details. There are two types of Burst of Power AA, one (SPA 177) for classes that have double attack skill, and another (SPA 225) for the classes that don't. For beast lords and bards that don't have the skill, SPA 225 does two things: it grants the skill and it increases the chances. Worn item effect of Ferocity also uses SPA 177 and that only increases double attack chance, but is not enabling of the skill. ps: Don't forget Rabid Bear AA (SPA 225) means that shaman get some benefit from Ferocity too.
