Proc BasicsProcs are effects that have a chance of occurring under a certain triggering condition. Typically this is used to mean effects that trigger off physical attacks or spellcasts; however, the term also can be used to apply to events that are triggered by being hit, such as the effect on [Bulwark of Azzinoth] or [Band of the Eternal Defender]. For purposes of this article I will be using the terminology of on-attack procs, but the principals here apply equally to procs of other sorts.Fundamentally, there are two important things to know about a proc: its proc chance, and it's internal cooldown.[top]Proc ChanceProcs generally fall under one of two categories. The first catagory are fixed-percent procs. No matter what weapon is used to trigger these, the chance that they will proc is the same. For instance, a Rogue's Combat Potency ability has a 20% chance to proc on all off-hand hits, regardless of the speed of the weapon used. If you attack once a second or once every 5 seconds, you will still proc on 20% of attacks. Similarly, [Sextant of Unstable Currents] has a 20% chance to proc on any spell critical strike, regardless of what spell is used.The second category is referred to as Proc Per Minute or "PPM" effects. These are normalized such that if you autoattack with a single weapon, the average number of procs you get in a minute does not depend on the speed of the weapon you use. So, as a simple example: Mongoose is thought to be a 1.2 PPM effect. Hence, if I autoattack with a 2.0 speed weapon, it will proc on 4% of attacks, such that over the course of a minute (during which I will make 60/2.0 = 30 attacks) it will on average proc 30 * .04 = 1.2 times. If, on the other hand, I autoattack with Mongoose on a 3.0 speed weapon, it will instead proc on 6% of attacks, such that it will still proc an average of 1.2 times per minute (60/3.0 = 20; 20 * .06 = 1.2).It should be noted that for any proc effect implemented in the Burning Crusade era (post-60), any haste effects in play are counted against your weapon speed for purposes of autoattacking. For instance, if I have 25% haste on, I will attack 25% more times in a minute, so each proc will be correspondingly less likely to proc such that I still average the same number of procs in a minute. Note that this is *not* true of pre-TBC proc effects such as Crusader - on these older effects, the chance of a proc going off is purely a function of your base weapon speed.Note, however, that this applies only to autoattacks. If one is additionally launching instant attacks - Sinister Strike, Mortal Strike, or whatever else - these have a chance to proc as well, and can thus increase the number of observed procs. Unlike autoattacks, haste effects do not reduce the proc rate of instant attacks; if you are using mongoose on a 3.0 speed weapon, you will have a 6% chance to proc no matter how much haste you have on.At this point an example would probably be helpful. Consider, for instance, [Madness of the Betrayer]. This is a trinket with a 1 PPM armor penetration proc. Let us assume for the moment that I am attacking with a 2.5 speed MH and a 1.5 speed OH. Let us further assume that I have 50% haste from various sources, and that I use Sinister Strike once every 4 seconds, and have WF totem. Then my MH autoattack occurs 36 times a minute, so each MH autoattack has a 2.78% chance to proc Madness of the Betrayer. However, those 36 attacks also proc an average of 7.2 WF procs per minute, which are considered autoattacks, so also proc at this rate. Thus, in reality I will generate (36 + 7.2) * 2.78 = 1.2 procs each minute from autoattack and Windfury. Now, my OH attacks can *also* proc Madness of the Betrayer, but since I average 60 attacks per minute with that weapon, each only has a 1.67% chance to proc. Thus, my OH generates 1 proc each minute on average as well. Finally, I make 15 instant attacks with Sinister Strike, each of which procs with a 4.17% chance (as the proc rate is note reduced by the haste effect in play). Thus, I get an additional 4.17 * 15 = .625 procs each minute from instant attacks. Thus, in the average minute, Madness of the Betrayer will proc 1.2 + 1 + .625 = 2.825 times each minute.

[top]Internal CooldownsSome trinkets additionally have an internal cooldown - that is, after a proc occurs, there is some duration that must elapse before the trinket can proc again. For instance, when [Band of the Eternal Champion] procs, it cannot do so again for 60 seconds. No two procs can ever occur less than 60 seconds apart. This is also an important aspect in determining the utility of a proc. It should be noted that all known procs either have an internal cooldown of 0 (that is, no cooldown at all) or an internal cooldown longer than the length of the buff. This fact will be important later.[top]UptimeWhat's really important in figuring out the usefulness of a typical buff is the uptime of the buff - that is, what portion of the time that buff is in effect.The easy case is addressing what happens when there is an internal cooldown longer than the length of the buff. If we defineD = Duration of the buffp = Chance the the buff procs on any given attackv = Number of attacks that can trigger the proc that occur in a given second, andc = Internal cooldown of the trinketU = uptime, thenU=\frac{D}{c+\frac{1}{vp}}The harder case is what happens when the proc does not have an internal cooldown. One might expect that if one had, say, a 1 PPM effect with a 15 second duration, the uptime would be 25% (15 seconds uptime per proc, one proc per 60 seconds, 15/60 = 25%). One would, alas, be incorrect. Because there is no internal cooldown, the procs can overlap, which reduces the actual uptime observed. The correct formula (using the same variables as above) is:U=1-(1-p)^{Dv}

Procs with/without internal cooldownsWhat is this all about?As has been pointed out before, most procs from trinkets have an internal cooldown which prevents them from chain proccing. Often, the cooldown is 3 times the proc duration, but some are longer, and some procs thad do do not give a buff for a certain duration incur a cooldown as well.As the value of an item may vary greatly, I'd love to gather the info about those trinkets to make comparing them somewhat easier.How does a proc with a cooldown work?If an item has a proc that lasts 15 seconds and has a 45 second cooldown, that means the following:If the item procs, you'll have the proc up for 15s and you will not have it up for the 30s after the proc faded. After those 45 seconds (counted from the start of the proc), the item can proc again with the listed chances.What happens if I have several trinkets with procs?From personal testing, they seem to act independently. I could have both trinkets proc at the same time, or a few seconds apart, and their buffs stacked. (This was with Shiffar's and Sextant, there are some reports from items seemingly sharing their cooldowns?)Are there some general guidelines?Few rules are without exception, and new items can always be different from everything before. However, the following held true for everything so far.- Weapon procs of the "Chance on hit: ..." type usually have no cooldown and can chain proc.- Weapon enchants of the "Chance on hit: ..." type usually have no cooldown and can chain proc.- Procs that are set bonuses from item sets usually have no cooldown.- Most meta gems do not have a cooldown and can chain proc.How does Spellsurge work?The weapon enchant Spellsurge (Spellsurge) may be a bit of an exception: It has a 10s duration, 50s cooldown, but it stacks with spellsurge enchants of other people in your group. In a group of 5 casters, it might eventually be able to stack with itself, but that is just speculation.Currently, I only have items listed that I've had the chance test myself. I really appreciate any further information about other procs, from casters and physical damage classes alike.I'd love to get as much information about procs as possible to make the available gear easier to compare.Procs without internal cooldownCrusader Enchant - Enchant Weapon - Crusader - +60 strength for 15s and 45-75 healed, 1 PPM on melee hit, no cooldownMongoose Enchant - Enchant Weapon - Mongoose - +120 agility and +2% melee haste for 15s, ~1 PPM on melee hit, no cooldownWindfury Totem - Windfury Totem - 20% chance on an extra attack with 445 extra attack power, no cooldown[Insightful Earthstorm Diamond] - 300 mana restored, 5% proc on spell cast, no cooldown[Darkmoon Card: Blue Dragon] - 100% mana regen for 15s, 2% proc on spell cast, no cooldown[Darkmoon Card: Twisting Nether] - resurrect with 20% HP/Mana, 10% proc on death, no cooldown[Eye of Gruul] - -450 reduced mana cost on next heal, 2% proc on heal, no cooldown; multiple proc chances from AoE heals

[Eye of Magtheridon] - +170 spell damge/healing for 10s, 100% on a full spell resist, no cooldown[Madness of the Betrayer] - +300 armour pentration for 10s, 1 PPM on melee/ranged hit, no cooldownAshtongue Talisman of ... - Ashtongue - various class-dependent procs, no cooldown[Wrath of Cenarius] - +132 spell damage for 10s, 5% proc on spell hit, no cooldown[Bulwark of Azzinoth] - +2000 AC for 10s, 2% chance on being hit, no internal cooldownSpellstrike Infusion 2/2 - Spellstrike Hood - +92 spell damage for 10s, 5% proc on harmful spell hit, no cooldownMalorne Raiment/Regalia 2/5 - Crown of Malorne - 120 mana restored on spell cast, ?% proc on helpful/harmful spellcast, no cooldownMalorne Harness 2/5 - Stag-Helm of Malorne - 10 rage/20 energy restored on melee hit, 4% proc on melee attack, no cooldownVoidheart Raiment 2/5 - Voidheart Crown - +135 fire/shadow damage for 15s, (10%?) proc on fire/shadow spell cast, no cooldownTirisfal Regalia 4/5 - Cowl of Tirisfal - +70 spell damage for 6s, 100% proc on spell crit, no cooldownProcs with a short cooldownWindfury Weapon (not Windfury Totem)- Windfury Weapon - 20% chance on two extra attacks with 445 extra attack power, 3s internal cooldown[The Lightning Capacitor] - 694-806 lightning damage after every 3 spell crits, 2.5s cooldown after a lightning shoots before crits start counting again[Mark of Defiance] - 128-172 mana restored, 15% proc on direct damage spell hit, ~15s cooldown.[Fel Reaver's Piston] - 500 healed over 15s, 15% proc on heal, ~15s cooldown[Timbal's Focusing Crystal] - 285-475 shadow damage, 10% proc on DoT tick, 15s cooldown[Dragonspine Trophy] - +325 haste rating for 10s, ~1 PPM proc on ranged/melee attack, 20s cooldown[Warp-Spring Coil] - +1000 armour penetration for 15s, 25% proc on special attack, 30s cooldownProcs with a long cooldown[Thundering Skyfire Diamond] - +240 haste rating for 10 seconds, 1 PPM on melee/ranged/shapeshifted attacks, 40s cooldown**[Mystical Skyfire Diamond] - +320 spell haste rating for 4 seconds, 15% proc on spell cast, 35s cooldownCooldown changed, not 100% certain[Warglaive of Azzinoth] - +450 haste rating for 10 seconds, 2% proc rate on melee attacks, 45s cooldown[Scarab of the Infinite Cycle] - +320 spell haste rating for 6s, 10% proc on heal, 45s cooldown[Bangle of Endless Blessings] - +15% mana regeneration while casting for 15s, 10% proc on spell cast, 45s cooldown[Fathom-Brooch of the Tidewalker] - 335 mana restored, 15% proc on nature spell cast, 45s cooldown[Shiffar's Nexus-Horn] - +225 spell damage/healing for 10s, 20% proc on spell crit, 45s cooldown[Quagmirran's Eye] - +320 spell haste for 6s, 10% proc on harmful spell hit, 45s cooldown[Sextant of Unstable Currents] - +190 spell damage/healing for 15s, 20% proc on spell crit, 45s cooldown[Tome of Fiery Redemption] - +290 spell damage/healing for 15s, 15% proc on spell cast, 45s cooldown[Hourglass of the Unraveller] - +300 attack power for 10s, 10% proc on critical hit, ~45s cooldown[Shard of Contempt] - +230 attack power for 20s, 10% proc on hit, 45s cooldown[Tsunami Talisman] - +340 attack power for 10s, 10% proc on critical hit, 45s cooldown[Masquerade Gown] - +145 spirit for 15s, 10% proc on spell cast, ~45s cooldown[robes of the elder scribes] - +130 spell damage for 10s, 5% proc on spell cast, ~45s cooldown2.4声望项链一律15%触发几率，10秒持续，45秒内置CD[Band of the Eternal Champion] - +160 AP for 10s, 1 PPM proc on melee/ranged attack, 60s CD[Band of the Eternal Sage] - +95 damage/healing for 10s, 10% chance on offensive spell cast, 60s CD[Band of the Eternal Defender] - +800 AC for 10s, 3% (?) on being hit, 60s CD[Band of the Eternal Restorer] - +175 healing (and damage) for 15s (10s?), 10% chance on heal cast, 60s CD

特效。。。好长