In Clair Obscur: Expedition 33 you upgrade weapons by talking to the Curator at camp during Act I, and from Act II onward by choosing Upgrade Weapons at any Expedition Flag, paying Chroma plus a Chroma Catalyst of the right tier for each level. Every weapon unlocks a passive effect at level 4, level 10 and level 20, and level 33 is the cap. This guide covers where to upgrade, what each tier of catalyst does, where the catalysts come from, which weapons deserve the investment, and what the patches since launch changed.
Where to upgrade weapons
The option lives in two places depending on how far you are:
- Act I: upgrades are handled by the Curator, an NPC who appears at camp once camping unlocks partway through the act. Speak to him and pick the weapon upgrade option. See our camp guide for how to set up camp in the first place.
- Act II onward: interact with any Expedition Flag and select Upgrade Weapons from the flag menu, which also holds Rest, Fast Travel, Upgrade Attributes, Learn Skills and Upgrade Expedition Resources. Player guides put the switch at the start of Act II.
Inside the menu, pick a character, pick the weapon, and confirm each level one at a time; each level shows its Chroma cost and the catalyst it needs. Hotfix 1.5.1 (December 2025) fixed a bug where “spamming Upgrade weapon and change character buttons” could push a weapon to level 34 and reverted those weapons to 33.
Chroma Catalyst tiers and what they cover
Every level costs Chroma, the currency you earn from battles and pick up in the world, plus one or more catalysts. The tier of catalyst rises with the weapon’s level:
- Chroma Catalyst: levels 2 to 3
- Polished Chroma Catalyst: levels 4 to 9
- Resplendent Chroma Catalyst: levels 10 to 19
- Grandiose Chroma Catalyst: levels 20 to 32
- Perfect Chroma Catalyst: level 33
The number of catalysts per level and the Chroma cost differ by weapon, so read the row before confirming. Per player-maintained weapon tables, a starting weapon climbs from roughly 50 Power at level 1 to several thousand at level 33, which is why weapon level matters more than almost any other upgrade.
Catalysts come from chests, enemy and boss drops, Gestral merchants, and side quest rewards. Grandiose catalysts are concentrated in the Act III challenge areas, and Perfect catalysts are scarce enough that most players max only a handful of weapons in a first playthrough, with New Game Plus making them easier to farm.
Levels 4, 10 and 20 are the ones that matter
Beyond raw Power, each weapon carries three passive effects that switch on at level 4, level 10 and level 20. The official patch notes refer to these directly (patch 1.5.6 fixed “Cleim weapon level 10 Lumina effect” and “Sireso weapon, Level 4 Lumina”), and the thresholds are the same on every weapon. In practice:
- Getting a new weapon to level 4 costs only common and Polished catalysts and unlocks its first passive, so it is almost always worth doing to test the weapon.
- Level 10 unlocks the second passive and is a sensible stopping point for a weapon you like but are not sure you will keep.
- Level 20 unlocks the third passive and starts the Grandiose tier, so only push past it on a weapon you intend to use for the rest of the game.
Every weapon also scales with two attributes, shown as letter grades from D up to S that improve as the weapon levels, so match your attribute points to those grades.
Which weapons to prioritise
Our rule of thumb is to level your main damage dealer’s weapon to 20 first, get everyone else’s current weapon to 4 or 10, and hold Grandiose and Perfect catalysts until you have settled on a final loadout. There is no option to reverse an upgrade or refund catalysts, so a Perfect catalyst on a weapon you drop an hour later is the one real mistake here.
Two more things help. Per Game8’s weapon guide, picking up a duplicate of a weapon you already own raises that weapon’s level without spending catalysts, so do not sell duplicates on reflex. And weapon passives interact with the Pictos and Luminas system, which is where most of the game’s depth lives; our Colour of Lumina guide and tips guide cover that side.
What changed since launch
The 2025 version of this guide put the Curator at every camp for the whole game, which was only right for Act I, and the balance has moved since. Verified against the official patch notes:
- Patch 1.2.3 (May 2025) fixed attribute scaling on Lithelim and Blizzon at high level (both now start a grade lower and gain a second scaling attribute), fixed Medalum’s third Lumina doubling all damage instead of only Burn damage, and cut Stendhal’s damage by 40 percent.
- Patch 1.3.0 (June 2025) fixed the Simoso weapon causing lag through a memory leak.
- Patch 1.5.0 (December 2025) added new weapons alongside Verso’s Drafts and the new Endless Tower bosses.
- Hotfix 1.5.1 (December 2025) fixed Monoco’s weapon Cannaro being unobtainable from Chromatic Machinapieds (players who had already beaten it received the weapon automatically) and fixed the level 34 exploit.
- Patch 1.5.6 (June 2026) fixed the Cleim level 10 effect not triggering on every instance of area-of-effect skills and the Sireso level 4 Lumina overriding the Powerful buff at the start of battle.
Every other Expedition 33 post is on the Expedition 33 hub.
Frequently Asked Questions
Where do I upgrade weapons in Expedition 33? At the Curator in camp during Act I, then at any Expedition Flag under Upgrade Weapons from Act II onward.
What is the max weapon level? Level 33. A hotfix in December 2025 removed a bug that let weapons reach 34 and reverted them to 33.
What do Chroma Catalysts do? Each weapon level needs Chroma plus a catalyst of the right tier: Chroma Catalyst to level 3, Polished to 9, Resplendent to 19, Grandiose to 32, and Perfect for level 33.
Which weapon levels unlock passives? Levels 4, 10 and 20. Each unlocks one of the weapon’s three built-in effects, which the patch notes call the weapon’s Lumina effects.
Can I undo a weapon upgrade? No. There is no downgrade or refund option in the upgrade menu, so save the rare catalysts for weapons you plan to keep.