Risk of Rain 2 mechanics, under the hood.

What a run looks like.

Your ship crashes on Petrichor V and you have to get out. Each stage is an open map with a hidden teleporter. Find it, activate it, survive while it charges (a boss appears) and move on to the next map. Along the way you open chests with the gold enemies drop and collect items.

After the fifth stage you can go for the final boss or keep going: if you keep going, the run starts again from the first map with everything you carry. That is looping, and the game becomes something else.

There are three difficulties: Drizzle (easy, with extra armour and more regen), Rainstorm (normal) and Monsoon (hard: less regen and difficulty climbs faster).

Time is the enemy.

Top right there is a bar that keeps climbing. Difficulty rises with minutes, not stages: enemies spawn at higher level, with more health and more often the longer you play. Chests cost more too.

That is why clearing every corner does not pay: opening a whole map might get you five items and cost you a difficulty step for the rest of the run. Most players' rule: open what is on the way, find the teleporter and move on.

In a group, the bar runs a bit faster and chests cost more from the start, although enemies still start at level 1.

Items, rarities and where they come from.

• White (common), green (uncommon) and red (legendary): from small, large and legendary chests.
• Yellow (boss): dropped by the teleporter boss, some guardians and Cleansing Pools (in exchange for a lunar item).
• Lunar (blue): bought with Lunar Coins, which carry over between runs. They always have a price: they give a lot and take something.
• Void (purple, Survivors of the Void): they «corrupt» a normal item and replace it. Picking one up converts every copy of its pair you hold.
• Equipment (orange): one at a time, used with a key, with its own cooldown.

3D Printers swap one of your items for the one they show, and Scrappers turn an item you do not want into scrap that printers take before your items. Together they let you shape the run instead of relying on luck. More in shrines, chests and portals.

How damage is calculated.

Your survivor has a base damage: 12 at level 1 for almost everyone, plus 2.4 per level. Skills list theirs as a percentage: 600% is six times that, 72 at level 1.

Items that deal extra damage work it out in one of two ways:

• A share of the hit that triggered them. The Ukulele lightning deals 80% of that hit: if the hit was huge, so is the lightning. They shine on big hitters like Loader.
• A share of your base damage, whatever the hit. Ceremonial Dagger daggers deal 150% of your base damage even if you killed with a weak hit.

What triggers your items.

Many items work «on hit»: 10% of your hits bleed, 25% release lightning... But not every hit counts the same. The game gives each attack a hidden number (the proc coefficient) that says how much it counts:

• A hit that counts fully has the full chance: Tri-Tip Dagger bleeds 10% of the time.
• A hit that counts half has half the chance: 5%. And the bleed lasts half as long.
• Attacks that hit very fast or many targets at once usually count little, so things do not trigger nonstop. Commando's Double Tap is the exception: very fast and counts fully.
• What items release counts too: the AtG Missile Mk. 1 missile counts fully and can trigger more items; the Ukulele lightning, very little.
• Crit is not affected: at 100% crit, every hit crits.

Stacking the same item.

Every item can be picked up more than once and the effect almost always grows. It grows in one of three ways:

Each copy adds the same most items

Soldier's Syringe: 15% more attack speed each; ten are 150%. Tri-Tip Dagger: 10% more bleed chance each.

Each copy adds a bit less never reaches 100%

For things that would be unfair at 100%, like blocking hits. Tougher Times blocks 13% of hits with one and 60% with ten, but never all.

Each copy multiplies very few

Shaped Glass: each doubles your damage and halves your health; with three, eight times the damage and an eighth of the health. Fuel Cell trims equipment cooldown a bit each time, but never to zero.

Watch out: sometimes the chance does not go up

On some items, more copies do not trigger more often; they hit harder instead:

• Ukulele: always 25%; each extra one makes the lightning jump to 2 more enemies.
• AtG Missile Mk. 1: always 10%; each extra one makes the missile stronger.
• Happiest Mask: always 7%; each extra one makes the ghost last 30 seconds longer.
• Lens-Maker's Glasses: past ten they do nothing more.

Every item, with what each copy adds, in the item list.

Crits.

A crit deals double damage. Each Lens-Maker's Glasses gives 10% chance (ten are 100%). Predatory Instincts, Harvester's Scythe and Shatterspleen give 5% more, but only the first of each.

Laser Scope changes the maths: with one, crits deal triple instead of double. So once your crit chance is high (or guaranteed, like Bandit from behind), a scope is worth more than another pair of glasses.

Items that do something «on crit» (heal, run faster, bleed) work on every hit once you reach 100%.

Luck.

57 Leaf Clover does not raise percentages: when a random roll fails, it rerolls once more per clover. It works for almost everything chance-based except Tougher Times, and it does not change what chests drop.

Purity does the opposite: it rolls once more so it fails, in exchange for lower cooldowns. With it, items that can reach 100% (glasses, Tri-Tip Dagger, Sticky Bomb) still work; those that cannot (Ukulele, missiles, hooks, Bandolier) dim a lot.

Chain reactions.

What an item releases can trigger others, if it counts for items:

• You shoot and an AtG Missile Mk. 1 missile fires. The missile counts fully: on hit it can release Ukulele lightning and bleed with Tri-Tip Dagger.
• The Ukulele lightning counts very little: it can trigger more things, but rarely.
• Brilliant Behemoth and Sticky Bomb explosions do not count: they deal damage but trigger nothing else.

That is why the same item is amazing on one survivor and weak on another: it depends on how many hits they land and how much those hits count.

What is most dangerous.

There is no public stat for which enemies kill the most players (neither the studio nor Steam publish one). What is known is which attacks hurt most and why:

• Elites: normal enemies with a power (fire, ice, lightning...) and much more health and damage. Lightning ones leave bombs when they hit you and ice ones explode on death.
• Black Void spheres: when Void Reavers die they leave an implosion that takes a huge amount of health and that Tougher Times does not block. Get out of it.
• Mithrix, the final boss: in his last phase he steals your items.
• Time: what kills the most runs is reaching a stage late with very high difficulty.

Every boss, with how to dodge each attack, in the boss guide.

Playing in a group.

• Up to four players. Each picks up their own items; chests cost more and difficulty climbs a bit faster.
• A fallen ally comes back on the next stage. With Dio's Best Friend they come back on the spot.
• Bandolier ammo packs can be picked up by any ally, not only whoever carries the item.
• Better to share than to give everything to one player: an on-hit item does more on whoever hits most, and a defensive one on whoever takes the most hits.

FAQ.

Numbers from the Risk of Rain 2 wiki as of 29 October 2026. Names: the game's own English names.