Duet Night Abyss doesn’t lock weapons behind gacha. Every weapon is earned in-game through a loop of farming Secret Letters, clearing Covert Commissions for a blueprint, and then crafting the weapon at the Forge. Here’s how the whole pipeline works, what you need to unlock first, and where to focus your time so new gear comes online faster.

Weapon unlocking overview

  • You need a weapon’s blueprint first. Blueprints are rewarded from Covert Commissions when you spend the correct Secret Letter.
  • To enter the pipeline, convert 10 Secret Letter Clues into one Secret Letter, then complete a matching Commission to roll for a drop.
  • Once a blueprint drops, craft the weapon at the Forge using materials, components, and coins. The same Secret Letter category that drops the blueprint also drops the crafting materials you’ll need.
  • Alternate paths exist: some weapons can be purchased directly with Phoxene Plumules (premium currency), and certain Trial Rank milestones grant specific weapons.
Note: Covert Commissions are fixed at level 40. Progress the main story and shore up your build before you farm them consistently.

Unlock the Forge (one-time story step)

Early in Chapter One, the side quest The Wandering Luno introduces Lunosmith and permanently unlocks the Forge in your Sanctuary. As part of the quest, you receive a blueprint and materials to craft Flamme de Epuration, a flamethrower-style ranged weapon, which also serves as your first crafting tutorial.

After this quest, you can access the Forge from the pause menu or by visiting Lunosmith in the Sanctuary. The Forge includes a Blueprints Compendium that shows each item’s material tree, coin cost, and wait time.

Farm Secret Letters and Clues

Secret Letters fuel the unlock loop. You exchange 10 Secret Letter Clues for one Secret Letter, then use that Letter when you complete a Commission to pull from its reward pool.

Clues are sprinkled across the game:

  • Main story and side quests: rich early sources to kickstart Letters.
  • Dailies and weeklies: reliable trickle; daily objectives yield 15 Secret Letter Clues.
  • Mystic Maze: a weekly roguelike mode that grants 30 Secret Letter Clues per week.
  • Immersive Theater: time-limited endgame stages tied to the newest release cadence, with up to 280 Secret Letter Clues per refresh.
Tip: Always match the Letter type to your goal. If you’re chasing a weapon, spend a Weapon Secret Letter on a Weapon Commission, not Character or Demon Wedge.

Run Covert Commissions for weapon blueprints

Covert Commissions come in three categories — Character, Weapon, and Demon Wedge — and their objectives rotate hourly. Rewards stay tied to the category; only the mission format changes.

  • Bring a Weapon Secret Letter into a Weapon Commission. After a successful clear, you’ll be shown three items drawn from that Letter’s pool and you can pick one.
  • Blueprints are not guaranteed. Expect several clears before the right blueprint appears in your three-item selection.
  • Weapon components and core materials also drop from the same Weapon Letters, so your farming contributes to both the unlock and the eventual crafting.

If you’re also farming characters, Commissions can drop Thoughts, and it takes 30 Thoughts to unlock a character. Gold-tier rewards like 10 Thoughts have low drop rates, so pace your expectations.

Craft the weapon at the Forge

With the blueprint in hand, head to the Forge. Every weapon requires:

  • Basic materials and coins from enemies, quests, and Commission rewards.
  • Weapon components sourced from Commissions; intermediate and advanced components can also be crafted in the Forge using coins and base parts.

Crafting often includes a wait timer. If you want to finish immediately, use Toy Hammers to skip time — each Hammer skips up to 10 minutes. They’re sold in the Prism shop in packs of two for 1 Lucent Prism.

Event cadence that affects weapons

The game spotlights new releases on a predictable schedule:

  • Immersive Theater features the newest character for 28 days and also ties in their signature weapon. Clearing stages during this window grants Secret Letters for that character and their weapon.
  • After the 28-day window, featured character Letters move to Nocturnal Echoes weekly bosses, then eventually appear in the shop’s Clue exchange. Signature weapon access follows the same rhythm via Secret Letters; you’ll still need a blueprint drop and Forge time to finish the weapon.
Tip: If your team can consistently hit high ratings in Immersive Theater, this is the fastest way to target-farm Letters for the newest character-and-weapon pair.

Other ways to obtain weapons

  • Premium purchase: You can buy a weapon outright in the in-game shop for 3280 Phoxene Plumules.
  • Trial Rank rewards: Leveling your account unlocks milestone rewards; some thresholds grant specific weapons such as the Ironforger greatsword.

These paths skip blueprint RNG but won’t replace the need to farm materials if you plan to craft additional weapons or components.

Quick reference: end-to-end flow

Step Action Where Outcome
1 Complete “The Wandering Luno” Chapter One side quest Forge unlocked; first weapon crafted (tutorial)
2 Earn Secret Letter Clues Dailies, story/side quests, Mystic Maze, Immersive Theater 10 Clues = 1 Secret Letter
3 Target Weapon Commissions Covert Commissions (level 40) Pick 1 of 3 rewards; roll for weapon blueprint and materials
4 Craft at the Forge Sanctuary or pause menu Spend blueprint, components, materials, and coins; wait timer applies
5 Optional time skip Prism shop → Toy Hammers Skip up to 10 minutes per Hammer to finish crafts sooner

If you focus your weekly loop on Clues from dailies, Mystic Maze, and Immersive Theater, then funnel Weapon Letters into Covert Commissions, you’ll steadily convert runs into blueprints and finish crafts as your materials cache grows. New banners shift the best farming spots, but the core loop — Letters → Commission → Blueprint → Forge — stays the same.