Risk of Rain 2 gives players the chance to turn their middling survivors into all-powerful demigods with the help of items. Many of these items activate certain effects based chance. However, the existence of proc coefficients makes things a little bit more complicated than what they appear on the surface.
Proc coefficients have been in many different games throughout history, and some of the strongest items in ROR 2 are subject to it. It’s not a terribly complicated concept, but it has a significant effect on how certain survivors play. If you’re wondering what a proc coefficient is, here’s what you need to know about it and more.
What Is A Proc Coefficient In ROR 2?
A proc coefficient is a multiplier that determines the duration and/or trigger chance of items with on-hit effects, such as Sticky Bomb and Stun Grenade. Basically, it is a second layer of RNG that’s meant to keep certain attacks and effects from becoming too powerful.
For the uninitiated, “proc” in a gaming context often refers to effects triggered by chance.
Example 1 – Ukulele
For example, the Flame Bolt skill of ROR 2’s Artificer class has a proc coefficient of 1.0 per hit. If you hit an enemy with Flame Bolt while having an item like the Ukulele, which has a 25% chance to trigger, you will always have a 25% chance of triggering Ukulele’s chain lightning effect (25 x 1.0 = 25). Meanwhile, if we take MUL-T’s Nailgun, which has a proc coefficient of 0.6 per hit, Ukulele only has a 15% chance to trigger on-hit (25 x 0.6 = 15).
Example 2 – Tri-Tip Dagger
Another example: Tri-Tip Dagger has a proc chance of 10%, and its effect lasts for three seconds. MUL-T’s Nailgun, with its 0.6 proc coefficient, has a 6% chance to proc Tri-Tip Dagger per hit. However, Tri-Tip Dagger’s bleed is also affected by proc coefficients — in MUL-T’s case, a dagger bleed proc should last around 1.8 seconds, but further testing shows that it actually lasts for two seconds. If Tri-Tip Dagger procs on the Primary Skill of a different ROR 2 character like the Railgunner, it will run its full course and have its full 10% chance to trigger.
As a rule of thumb, fast and multi-hit attacks like MUL-T’s Nailgun, Huntress’ Volley, and Void Fiend’s Corrupted Drown have lower proc coefficients. There are exceptions, like Commando’s Double Tap and Artificer’s Flamethrower.
What Are Proc Chains?
A proc chain is what happens when on-hit effects trigger other on-hit effects. The prime example of this is the Ukulele + AtG Missile combo. Ukulele lightning strikes have a proc coefficient of 0.2, which means they have a 2% chance of launching an AtG rocket. Likewise, rockets have a 1.0 proc coefficient, giving them a 25% chance to trigger chain lightning strikes.
The fact that on-hit effects can trigger off each other is the reason why 57 Leaf Clover is one of the best red items in ROR 2. It gives all random item effects an additional roll, and the game picks whichever roll is favorable (in layman’s terms, it makes you luckier). A single hit can result in a cascade of damage that can potentially wipe out all enemies on-screen. Keep in mind that damage-over-time effects like Bleed and Burn have a proc coefficient of 0.0, and thus cannot trigger on-hit effects themselves.
Damage dealt by items is often based on the base damage of whatever attack triggered the effect. Also, Critical hit chance is not affected by proc coefficients.