I had heard grumblings that on TLPs, Ferocity didn't affect Bards until a certain expansion due to the AA nature of Bard Double Attack. I did some light testing. Maybe I'm the only one who was even concerned, and this was a waste of time. TL;DR: Ferocity seems to be working as expected on Bards This is during DoN era with a level 70 Bard and all relevant AAs (Burst of Power 5 - 15% chance to Double attack). Ferocity V lists a Double attack increase of an additional 15%. 15% of 15% is 2.25%, so I'd expect a 2.25 percentage point increase on double attack rate. The item I tested with was Shoulderpads of Warfare. First a baseline without them equipped, then a parse with them equipped. The parses were ~20minutes each because there are no parse dummies so I couldn't just afk overnight for a consistent long duration parse. I equipped a Rusty Short Sword (28 delay) and my only buff was Symphony of Battle. With OH AAs, I was at 208 haste, for an effective delay of just over 1.3 seconds. Offhand held a drum to eliminate dual wields. Parse target was a 70 druid using /duel. Druid facing away from Bard throughout parse. Without Ferocity: Double Attack rate of 12.9% Total Attacks: 1162 Double Attacks: 150 Double Attack Rate: 0.12908777969018934 Ferocity V: Double Attack rate of 15.3% Total Attacks: 1035 Double Attacks: 159 Double Attack Rate: 0.1536231884057971 These are fairly small sample sizes, but I think it shows a statistically significant difference. In both cases, the rate is slightly below what I'd expect since it should be a base of 15% (according to the AA description). This could be due to the parser being consistent, but not 100% accurate. I hacked the parser together in a few minutes just to test Double Attack rate, so it's not been thoroughly vetted or anything. The code is here: DoubleAttackParser/Parser.html at main · Trebla7th/DoubleAttackParser (github.com) I can post the full parses if anyone is really interested, but since the data doesn't show anything aberrant, I don't see a point.
If you have an item with Ferocity (SPA 177 - Double Attack Chance), but do not have either the Double Attack skill or SPA 225 (Burst of Power - Grant Double Attack), Double Attack won't work. If you have Burst of Power, you can get a bonus from Ferocity as well. Interestingly, the chance to double attack is slightly different if you do not have the skill. Chance to Double Attack: If you do not have the Double Attack skill or SPA 225 (Burst of Power), exit If you have the Double Attack skill, Chance = Skill + Level (PC Level). Otherwise, Chance is 0. Bonus = 500 * SPA 225 / 100 Chance += Bonus If you have SPA 177 (Ferocity), Chance += Chance * SPA 177 / 100 Roll 1-500. If you roll below your chance, it's a successful Double Attack. Written more simply: *Only include Skill + Level if Skill > 0 DoubleAttackChance = (Skill + Level)* + 500 * SPA 225 / 100DoubleAttackChance += DoubleAttackChance * SPA 177 / 100DoubleAttackChance /= 500For a level 70 Bard in DoN with Ferocity V and Burst of Power 5: Skill = 0 Level = 70 SPA 225 = 15 SPA 177 = 15 Chance = 17.2% For a level 120 Bard in ToL with Ferocity XIII (or higher) and Burst of Power 62 (from TDS, or higher): Skill = 250 Level = 120 SPA 225 = 45 SPA 177 = 21 Chance = 143.8%
To see posts like this from the devs is really cool! Much of the old research us players did on subjects like this vanished with TSW. While I never did double attack parsing (Clerics never had it then!), I still remember testing things like Improved Dodge and Dodge % in the arena or elsewhere with jt_buff in order to come up with equations like these. It's neat to know we were on the right track all along.