The tooltip for Righteous Fury specifies the following:
Increases the threat generated by your Holy attacks by 60%. Lasts 30 min.
In practice, however, Righteous Fury increases the threat of ALL spells in the Holy school, such that it affects the threat generated by blessings, heals, etc, which vastly improves the threat potential of Protection Paladins, as shown in the two videos linked below.
A very notable property of Righteous Fury is that it uses the same Aura as Defensive Stance.
The only difference is that Righteous Fury only affects Holy spells, whereas Defensive stance affects physical spells.
Brief History of Righteous Fury:
Righteous Fury was implemented in Patch 1.9.0 “The Gates of Ahn’Qiraj” as part of the Paladin overhaul, replacing the Seal of Fury ability as a threat generation ability.
For the remainder of WoW Vanilla’s lifespan, Righteous Fury has only had two updates.
Patch 1.9.3: "Greater Blessing of Sanctuary - Paladins with Righteous Fury will now generate extra threat correctly when this Blessing procs. "
Patch 1.10.0: " Righteous Fury - Righteous Fury will now always generate the correct amount of additional threat on all holy damage. There were some abilities, such as Retribution Aura, where this did not work correctly. "
In TBC and afterwards, Righteous Fury’s tooltip was updated to include all Holy Spells, rather than just Holy Attacks. It’s as if the “bug” was later adapted into the ability description.
Is this a bug?
Yes. In a recent conversation between a member of the Classic Paladin community and Kevin Jordan, former Game Designer at Blizzard who designed nearly all the spells for all the classes available in vanilla World of Warcraft, it was confirmed that Righteous Fury was only supposed to affect Holy attacks, and was therefore a bug.
Q: “was RF supposed to boost threat from everything and not just holy dmg abilities?”
Kevin: “Holy attacks only.”
Q: “ok so then this is a bug?”
Kevin: “If it’s modifying greater blessing threat generation, yes.”
However, later in the conversation, another paladin community member brought up that Righteous Fury and Defensive Stance both use SPELL_AURA_MOD_THREAT , to which Kevin replied,
“Yes, it makes sense that Defensive Stance and Righteous Fury would be built the same but there may have been (or should have been) a script attached to Righteous Fury to limit it to attacks only. The warrior doesn’t have as many buffs as the paladin which is the reason the tooltips read the way they do to prevent that awkward paladin play pattern. Something we may have missed back then though. We also have #nochanges to contend with.”
It’s a bug, but should it be left untouched?
Clearly, it was not intentional for non-damaging Holy Spells to be affected by Righteous Fury, however, as Kevin stated, the bug may never have been resolved for the remainder of Vanilla WoW’s history. It is very likely that this bug may never have been fixed because it never became an issue, as no one discovered this unintentional mechanic until WoW Classic’s release, 15 years later.
Looking at Defensive Stance as a precedent, since it affects the threat generated by Battle Shout, it would make sense for Righteous Fury to affect the threat generated by similar abilities such as Greater Blessing of Kings because RF and DS both use the same aura SPELL_AURA_MOD_THREAT.
Although not intentional, by virtue of being a mechanic/bug that was left untampered with for the lifespan of WoW Vanilla up until the launch of The Burning Crusade, it is my personal opinion that the Righteous Fury mechanic should remain in Classic in its current state under the #nochanges rule, regardless of it being a bug.