"Gain access to a Rusty Lockbox that contains a powerful item. A hidden cache containing an item (80%/20%) will appear in a random location on each stage. Opening the cache consumes this item." White common item unlocked via the Keyed Up challenge. One Rusty Lockbox spawns on the next stage for each player holding a key. The lockbox holds an 80% chance at an uncommon item or 20% chance at a legendary. One key is consumed per lockbox opened. Corrupted into Encrusted Key by SotV DLC.
Artifact Sacrifice
Still spawns
Void Version
Encrusted Key
How Rusted Key Works
Lockboxes spawn on the next stage, not the current one. Picking up a Rusted Key mid-stage does nothing for that stage. The Rusty Lockbox appears when you enter the following stage. Plan around this - if you find a key late in Stage 3, your lockbox appears in Stage 4.
One lockbox per player holding a key, not per key held. A player with 5 Rusted Keys still only generates one lockbox per stage. The number of lockboxes on a stage equals the number of distinct players who have at least one key. In multiplayer, if you have extra keys, open other players' lockboxes so they keep theirs.
Each lockbox opened consumes exactly one key. Opening a lockbox removes one Rusted Key from your inventory. To get a lockbox on the next stage you must still have a key remaining. Stack keys to guarantee a steady stream of lockboxes across many stages without running out.
Lockboxes spawn even with Artifact of Sacrifice active. Sacrifice removes regular chests and makes enemies drop items instead. Rusty Lockboxes are not classified as chests and are not affected by this artifact. This makes Rusted Keys uniquely valuable in Sacrifice runs since they are one of the only sources of guaranteed items outside of enemy drops.
Lockboxes blend into the environment - use teleporter events to locate them. The box is dark-colored and can be hard to spot against terrain. During a teleporter event, any lockbox outside the teleporter radius will be highlighted by orange tendrils. Use this as your primary method for locating them before the event ends and you move on.
Lockbox Odds vs Other Sources
Rusty Lockbox
= Large Chest
Encrusted Cache (Void version)
3 void choices
Note: In-game description says 60%/30%/10% - effective odds after drop bias are approximately 42%/51%/7%.
The Rusty Lockbox gives better legendary odds than the Encrusted Cache. 20% chance at a red vs ~7% effective chance at a void red. If your goal is red items, Rusted Key outperforms Encrusted Key. However, Encrusted Cache gives you a choice between three void items - useful if you are specifically targeting a void item for a build.
Rusted Key vs Encrusted Key
Rusted Key - Keep This When:
+You want consistent green/red item access every stage
+You are playing long looping runs where green stacks compound
+You have Artifact of Sacrifice active (lockboxes are your main item source)
+You want the 20% legendary chance (better than Encrusted Cache's ~7%)
+You are not planning to fight Mithrix (looping preference)
Encrusted Key - Better When:
+You are targeting a specific void item for your build
+You are fighting Mithrix (void items often have better single-target focus)
+You want to choose from 3 options rather than accept a random item
-Lower effective legendary odds (~7% vs 20%)
-Corrupts all Rusted Keys on pickup - no going back
Multiplayer Rules
One lockbox per player holding a key, regardless of key count. In a 4-player game where all 4 players hold at least 1 key, 4 lockboxes spawn per stage. A player with 10 keys and a player with 1 key each generate exactly one lockbox. The total lockbox count equals the number of players with keys.
Any player can open any other player's lockbox. Lockboxes are not bound to the player who generated them. If Player A has the key and the lockbox spawns, Player B can walk up and open it. One of Player A's keys is consumed, and Player B gets the item. Coordinate this in multiplayer to maximize efficiency.
Players with many keys should open lockboxes for keyless players. If one player has 5 keys and another has 0, the 5-key player should open the lockboxes on behalf of others whenever possible. This lets each player maintain at least 1 key for future stage spawns while the excess keys are used to open extra boxes this stage.
How to Unlock - Keyed Up Challenge
Defeat a Teleporter Boss within 15 seconds of it spawning
1
Build damage items early in the run - you need burst DPS to kill a boss in 15 seconds.2
Use Shrine of the Mountain to spawn multiple bosses - any one of them dying within 15 seconds counts, but more bosses means more health to get through.3
Artifact of Command lets you select specific items - stack damage reds like Laser Scope and AtG Missile Mk. 1 for the burst window.4
The 15-second window starts the moment the boss spawns, not when you start charging the teleporter. Position yourself near where the boss spawns and burst immediately.
Easiest on Stage 1 where boss HP is lowest. Vagrants and Stone Titans have predictable movement. Void Fields bosses do not count toward Keyed Up.
Frequently Asked Questions
What does the Rusted Key do in Risk of Rain 2?
The Rusted Key is a white common item that causes a Rusty Lockbox to spawn somewhere on the next stage for each player who holds one. Opening the lockbox consumes one key and gives an item with 80% chance at an uncommon (green) and 20% chance at a legendary (red). Lockboxes spawn even with Artifact of Sacrifice active since they are not classified as chests.
Does stacking Rusted Keys give better loot?
No, not anymore. The current patch fixed lockbox odds at 80% uncommon and 20% legendary regardless of how many keys you hold. Multiple keys are still useful because each stage only consumes one key per lockbox opened - holding 5 keys means you get a free lockbox for 5 consecutive stages before running out. Stacking keys is about longevity, not rarity scaling.
When does the Rusty Lockbox spawn?
Lockboxes appear at the start of the stage after you pick up the key - not the current stage. If you find a key on Stage 2, your first lockbox appears on Stage 3. The lockbox spawns at a fixed but random location on the map when you enter the stage.
Where do you find the Rusty Lockbox?
The lockbox spawns at a random location on the stage and can be difficult to spot since it blends into the environment. The most reliable way to find it is during the teleporter event - any lockbox outside the event radius will appear with orange tendrils highlighting it. Explore the map fully before completing the teleporter if you want to find and open it before leaving the stage.
Should I use Rusted Key or Encrusted Key?
Rusted Key is better for looping runs where consistent green and red access per stage compounds over time. Encrusted Key is better if you are targeting a specific void item or fighting Mithrix where void items tend to have stronger single-target focus. Rusted Key also has significantly better legendary odds (20% vs ~7% effective for Encrusted). The Encrusted Key's main advantage is choice - you pick from three options rather than accepting a random item.
Does Rusted Key work with Artifact of Sacrifice?
Yes. Artifact of Sacrifice removes regular chests and makes enemies drop items instead, but Rusty Lockboxes are not classified as chests and are unaffected. This makes Rusted Key particularly strong in Sacrifice runs where it becomes one of your primary sources of guaranteed item rarity control rather than relying purely on enemy drop luck.
How do you unlock Rusted Key?
Complete the Keyed Up challenge by defeating a Teleporter Boss within 15 seconds of it spawning. The timer starts the moment the boss appears. Focus on Stage 1 where boss HP is lowest, stack early damage items, and burst the boss immediately on spawn. Completing the challenge also grants 1 Lunar Coin as a reward, and Rusted Keys begin appearing in item pools from your next run.
More RoR2 Item Guides
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