## Different Items Stack

Unmarked spoilers for several items. Viewer beware.

Risk of Rain 2 has several items which introduce different numerical modifiers to the same character values. This is a guide about how different items interact with the same stat.

If a piece of text says “any number”, assume that means the bonus/penalty does not increase with extra stacks.

All calculations should be done in the same order that each operation is listed here.

All info was gathered by decompiling the game.

Naturally, as this is an Early Access title, everything is subject to change.

## Attack Speed

- Additive boost of 12% attack speed per Predatory Instincts buff, number of buffs limited to 1 + (stacks * 2).
- Additive boost of 15% attack speed per Soldier’s Syringe.
- Additive boost of 30% attack speed if affected by any number of Warbanners.
- Additive boost of 100% attack speed while affected by any number of Berzerker’s Pauldrons.

## Critical Hit Chance

- Additive boost of 10% per Lens-Maker’s Glasses.
- Additive boost of 5% if carrying any number of Predatory Instincts.
- Additive boost of 5% if carrying any number of Wicked Rings (unimplemented).
- Additive boost of 5% if carrying any number of Harvester’s Scythes.
- Additive boost of 100% if under the effects of Ocular HUD.

Note the Predatory Instinct’s hidden crit chance.

## Cooldowns

- Multiplied by 75% for each Alien Head.
- Utility cooldown multiplicatively reduced by 33.3…% if carrying any number of Hardlight Afterburners.

## Health and Shields

- Additive +1 HP bonus per Infusion bonus (maximum of 100 per Infusion stack)
- Additive +40 HP bonus per Titanic Knurl.
- Multiplicative -50% HP penalty per Shaped Glass.
- If carrying Transcendence, all HP except 1 converted to shields at a 150% rate, increased by 25% for every stack after the first.
- Additive +25 Shields bonus per Personal Shield Generator.

## Armor

- Additive penalty of -20 if being crippled by any number of Effigies of Grief.
- Additive bonus of +30 while sprinting per Rose Buckler. The in-game text does not reflect the code.

## Health Regeneration

- Multiplied by 250% if Cautious Slug is active, with a +150% increase for every stack after the first.
- Additive bonus of 160% per Titanic Knurl.

## Movement

- Additive bonus of +30% movement speed per stack while the Red Whip is active.
- Additive bonus of +14% movement speed per Paul’s Goat Hoof.
- Additive bonus of +20% movement speed while using the Milky Chrysalis.
- Additive bonus of +30% movement speed while affected by any number of Warbanners.
- Additive bonus of +40% movement speed while affected by any number of Old War Stealthkits.
- Additive bonus of +50% movement speed while affected by any number of Berzerker’s Pauldrons.
- Multiplicative -50% movement speed penalty while crippled by any number of Effigies of Grief.
- Additive bonus of +30% movement speed if sprinting while carrying Energy Drinks, with a +20% bonus for every stack past the first.

This bonus specifically ignores your sprinting multiplier.