Last updated: 04/07/08, patch 2.4.
In the videogame world, the word “proc” describes something that can trigger or activate. Set bonuses, enchants, gems, trinkets, gear, and weapons … everywhere you look in Warcraft you see “Chance on <X> of <Y> (for <Z> seconds)”. This is a proc.
And for those of you who are curious of the etymology of the word “proc”, it is derived from the computer science phrase “programmed random occurrence.”
An example of a priestly item with a proc is the Masquerade Gown, out of Karazhan. It has a chance on spell cast to increase spirit by 145 for 15 secs.
In Warcraft, most procs have an internal cooldown that is unseen to us, the player. This is in place to prevent an item/bonus/etc. from getting too many procs back to back, or even simultaneously stacking.
Generally speaking, how the internal cooldown works is as follows: If an item has a proc that lasts for 20 seconds, and has a one minute (internal) cooldown, the proc will be up or active for 20 seconds, then there will be 40 seconds before it could feasibly happen again. 1 minute internal cooldown – 20 second proc = 40 seconds between procs, at minimum. Math ftw.
Well, how do we know how long the internal cooldown is, though? Well, by testing. Or by having others test for us.
How is this useful? Knowing the internal cooldowns of various items allows you do to some simple math to compare similar items to see which gives you the best benefit. It is extremely helpful to know about how many times you could see it proc over a long fight.
Here is a brief list of priestly items and their internal cooldowns:
- Spellsurge – 50s internal cooldown (but can still stack with other players’ Spellsurge buffs)
- Insightful Earthstorm Diamond – no internal cooldown
- Mystical Skyfire Diamond – 45s internal cooldown
- Darkmoon Card: Blue Dragon – no internal cooldown
- Darkmoon Card: Twisting Nether – no internal cooldown
- Wrath of Cenarius – no internal cooldown
- Eye of Magtheridon – no internal cooldown
- Mark of Defiance – 15s internal cooldown
- Fel Reaver’s Piston – 15s internal cooldown
- Scarab of the Infinite Cycle – 45s internal cooldown
- Bangle of Endless Blessings – 45s internal cooldown
- Shiffar’s Nexus-Horn – 45s internal cooldown
- Quagmirran’s Eye – 45s internal cooldown
- Sextant of Unstable Currents – 45s internal cooldown
- Spellstrike – no internal cooldown
- Ashtongue Talisman of Acumen – no internal cooldown
- Masquerade Gown – 45s internal cooldown
- Robe of the Elder Scribes – 45s internal cooldown
- Band of the Eternal Restorer – 45s internal cooldown
- Band of the Eternal Sage – 45s internal cooldown
- Shattered Sun Pendant of Restoration – 45s internal cooldown
- Shattered Sun Pendant of Acumen – 45s internal cooldown