Aggrend has by now thankfully divulged many of the specific functions of Nightfall to the public, such as it’s proc rate of 11.6% chance-on-hit as well as it’s categorization as being not negatively affected by Hamstring’s GCD in the Reference Client. However, in Classic over 4,000 attacks have been recorded with Nightfall while spamming the Hamstring ability almost every GCD and the results show an 8% chance-on-hit (which is consistent with the Hamstring 1.5s GCD blocking the 3.5 speed Nightfall’s auto-attacks from proccing).
This indicates that there is a bug involved, potentially involving the modern client misinterpreting Vanilla data that leads it to conflict with the Reference Client on the GCD interaction.
Thanks everyone for the additional reports and commentary about this over the past few days. I don’t want to go too into the weeds about this, but in an effort to be transparent and accurate, I did want to call out an error that we made in our previous post about this:
This statement is, simply put, incorrect. This ended up being a bit of a red herring during our investigation that at the time we believed explained some inconsistencies in our test results. After further review however, we discovered this was not correct and felt it was important to let all of you know that we had this wrong.
The “good” news is, the actual results from the comparison between original WoW and Classic was the same, and that the actual answer for why these items are bound by the GCD was far more mundane; some proc effects simply have a data flag set to obey GCDs, and the items listed in the original thread about this all have that data flag set in the 1.12 data. We still don’t consider this to be a bug as the fact that this was set in the original data even more strongly suggests that these effects were intended to behave this way from the start.
Again, sincere apologies for the bad info. While we feel its important that some sense of mystery remains in the game for players to discover and decipher, we at least want to present whatever information we do share to be correct and not contribute further to the misinformation that is common in discussions around game mechanics. We are still human and are not immune from making mistakes of our own, unfortunately.
Thanks for calling this (and us) out though, we really appreciate the dedication you all continue to show!