Duet Night Abyss progression explained — Secret Letters, Covert Commissions, and cosmetic gacha

Duet Night Abyss makes two bold choices: it leans into narrative ambiguity and it decouples playable characters from traditional gacha. If you’re wondering who to trust in the story and how to actually unlock characters, the short answer is: don’t stress the choices, learn the systems. Every character and weapon is obtainable for free through repeatable content, and cosmetics live on a separate gacha track.

Install Duet Night Abyss

Play on PC via the Epic Games Store. Use the product page to download and install: Duet Night Abyss on Epic Games Store.

Character unlocks: Secret Letters, Thoughts, and Introns

Characters, weapons, and Demon Wedges are tied to an item called a Secret Letter. You spend a Secret Letter after a Covert Commission (a repeatable mission) to claim rewards. Character unlocks come from “Thoughts” — collect 30 Thoughts for a specific character to add them to your roster.

Most of the cast joins naturally through the main story over time. For everyone else, Secret Letters let you target unlocks and power-ups. You’ll keep farming Secret Letters even after you recruit someone because Introns (think permanent character boost nodes) also come from this path.

Covert Commissions: how the loot actually rolls

Covert Commissions are endgame-tuned missions set at level 40. There are three categories — Character, Weapon, and Demon Wedge — and they rotate hourly with different objectives while keeping the same reward type.

• After you clear a commission and spend your Secret Letter, you’re presented with three items drawn from that letter’s loot pool. You can pick one.
• Gold-tier drops are rare. A pack of 10 Thoughts has a 10% drop chance; lower-tier items are more common.
• Weapons and Demon Wedges revolve around blueprints and materials. One blueprint drop unlocks the ability to forge, and the necessary crafting materials come from the same Secret Letter pool.

Getting Secret Letters: dailies, weeklies, and endgame modes

Secret Letters are minted by exchanging Secret Letter Clues. Early on, main story chapters and major side quests award a healthy chunk of Clues. After you clear those, you’ll rely on daily/weekly objectives and endgame activities.

Once you have 10 Secret Letter Clues, exchange them for one Secret Letter. Use letters that match your current target: Character, Weapon, or Demon Wedge, then clear the corresponding Covert Commission.

New character cadence: a rotating on-ramp, not a paywall

New characters follow a predictable funnel. At first, you can’t buy their Secret Letters using Clues in the shop. For the first 28 days, their Secret Letters appear as featured rewards in Immersive Theater. After 28 days, their letters move to Nocturnal Echoes’ weekly boss pool. Later, they land in the exchange shop alongside the rest.

At launch, Psyche is the Immersive Theater focus, with up to 65 Psyche Secret Letters and 50 for her signature weapon available through that mode. During the same window, Nocturnal Echoes bosses award Secret Letters for Tabethe, Truffle and Filbert, Yale, and Rhythm. Once Psyche leaves Immersive Theater, her letters shift to Nocturnal Echoes, rotating with the existing set.

This structure makes targeted farming realistic if your team can consistently hit high ratings in Immersive Theater. If you’d rather wait, every character eventually becomes obtainable through the standard exchange.

Cosmetics live on a separate gacha (with clear pity)

Characters and weapons aren’t on a gacha banner, but outfits are. The cosmetic system sits in Myriad with a limited banner and a standard banner. You’ll use Prismatic Hourglasses for limited-time outfits and Pristine Hourglasses for the standard pool; both come from events and logins, and can be purchased with the game’s paid currency.

• A purple-rarity item is guaranteed every 10 pulls.
• Hard pity grants 25 Iridescent Prisms after 90 rolls. Prisms are spent in the exchange for the featured skin or other items.
• Gold-rarity items have a 0.3% drop rate. Gold includes the featured outfit, a 25-Prism bundle, and a rarer 50-Prism bundle.
• There’s no soft pity, and pity doesn’t carry between banners.

There are also direct-purchase skins separate from the gacha. A seasonal outfit at launch is priced at about a dollar and can be applied to any character, with more shop additions planned over time.

Story choices and trust: moral gray by design

The narrative plays with perspective, often highlighting the “good side” of opposing factions. That framing creates intentional uncertainty about who to trust from scene to scene. Early on, “The Reborn” serves as the first main story mission and introduces the core systems before the plot starts twisting the lens.

Crucially, progression isn’t gated by how you resolve story tensions. You won’t lose access to playable characters based on narrative choices. If a favorite doesn’t arrive through the campaign, their Secret Letters and Thoughts are available through the repeatable loops outlined above.

What to do on day one

• Push the main story until you’re comfortable at level 40, then begin running Covert Commissions regularly.
• Convert Secret Letter Clues as you earn them and spend letters on the category you’re targeting.
• Hit your daily objectives for a steady 15 Clues per day, then clear Mystic Maze weekly and engage with Immersive Theater to stockpile Clues or featured character letters.
• Use Nocturnal Echoes weekly bosses to chase current-rotation character Secret Letters.

Once these loops are in place, building a roster is a function of time and focus rather than luck — leaving the gacha for cosmetics and the story to keep you guessing.