If you’re just jumping into Duet Night Abyss, the first few hours can feel overwhelming — so many systems, resources, and new terms like “Secret Letters” or “Demon Wedges.” Don’t worry — you can unlock basically everything in this game for free if you just know what to focus on first.
This Duet Night Abyss Progression Guide walks you through the full F2P progression path, from story progression to farming characters, weapons, and demon wedges efficiently.
Let’s start with the single most important rule every beginner needs to understand.
The Golden Rule
Before you start running around doing side stuff, focus on the main story.
Most of the game’s important systems — like your Sanctuary hub, forge, commissions, and character unlocks — stay locked until you clear the prologue and push into Chapter 1.
You can explore the Ice Lake area right away, but honestly, it’s not worth it early on. The story unlocks things way faster than exploration ever will.
The best part? There’s no stamina system here. You can take breaks, play at your own pace, and you’ll never “waste energy” by logging off. It’s a rare system for a gacha-style game — and it’s what makes DNA so chill to play long-term.
Character Unlock Timeline
Here’s how your character roster expands naturally just by following the story.
Margie joins you first. She’s solid for early AoE damage, but don’t dump resources into her right away — her sanity costs are rough in early levels. Once you hit around level 30–40, you’ll have the wedges to support her properly.
Berenica and Rebecca unlock once you reach your Sanctuary hub. At this point, it’s best to pick one carry — either your main character or Berenica — and funnel every resource into that one until you finish the story.
Rebecca deserves a special mention — she’s not only strong but also your future AFK farming machine once you hit level 40+. You’ll use her to power-level every new unit later on.
Outsider and Truffle & Filbert join as you move deeper into the campaign. Outsider is your single-target burst unit who deals more damage the lower his HP gets, while Truffle & Filbert are wind healers who buff Malaise (synergizes beautifully with Psyche if you get her later).
Daphne appears around Chapter 2 — another healer with buffing skills. Having her gives you more flexibility in support-heavy fights.
By the time you’ve unlocked all of these, you’ll be around level 40, ready to access every core farming system in the game.
The Secret Letter System
Once you hit level 40, you unlock Secret Letters — the real key to getting free characters, weapons, and demon wedges.
Here’s how it works:
You earn Secret Letter Clues (gray scrolls) by playing normally.
Daily quests give about 15 clues, so within two days, you’ll have enough to trade.
You need 10 clues to exchange for one Secret Letter for the character or weapon you want.
This system isn’t random — you pick exactly which letter to farm.
After that, go to Covert Operations from the combat menu. These missions rotate hourly and have three types:
- Character farming
- Weapon farming
- High-level demon wedge farming
Each mission has random objectives like killing 100 enemies or defending a tower, but they all drop rewards in three tiers — Bronze, Silver, and Gold.
Gold = 10 shards (10% chance)
Silver = 2 shards (guaranteed progress)
You need 30 shards to unlock a character. Even with average luck, you can unlock one within an hour of farming. The system has pity too, so eventually, you’re guaranteed to hit those gold drops.
It’s an insanely fair setup compared to other gachas — your time directly equals progress.
The 28-Day Character Cycl
When new characters release, they first appear in the Immersive Theater — an endgame mode that resets every 28 days.
You don’t need to be a whale to clear it either.
If you can beat the first difficulty tier and some of the second tier, you’ll earn enough rewards to unlock the new character outright. Higher-level players (around level 60+) can clear more nodes faster, but even level 40–50 players can grab new units with a bit of grinding.
After that 28-day window ends, that character moves to Nocturnal Echo — the weekly boss stage.
You can fight it five times per week to get their Secret Letters and signature weapon shards.
Once that event cycle ends, the character joins the standard exchange shop, meaning they become permanently farmable for everyone.
So yeah — patience literally pays off here.
How to Efficiently Use Secret Letters
When you’re ready to farm characters:
- Collect Secret Letter Clues from dailies or events.
- Trade 10 for the character-specific letter.
- Run Covert Missions and aim for the gold-tier rewards.
- Get 30 shards → unlock your character.
That’s it.
For weapons, it’s the exact same system, just through the Weapons tab instead.
And for Demon Wedges, you’ll unlock their missions later — still under Covert Operations.
The Resource Funneling Trick
If you’re free-to-play, here’s the best advice you’ll ever get:
Do not level multiple characters early on.
Focus on one carry character (either your MC or Berenica) until you finish the story.
Why?
Because everything — from EXP to resources — multiplies faster at higher stages. Instead of struggling in early content with a weak team, it’s more efficient to blast through the story with one strong unit.
Then once you reach level 40+, use that main to power-level everyone else through Covert Missions.
Each commission gives tons of EXP to your active character. With the right setup, one mission can jump a character two whole levels.
Rebecca
Once you’ve cleared the story and unlocked full farming, it’s time to shift gears. Start dumping your resources into Rebecca.
She’s easily one of the best F2P-friendly characters in the game — her kit is perfect for AFK farming commissions.
Here’s the trick: you let Rebecca fight while keeping your new character active in the slot. Since EXP goes to the active character no matter who’s doing the fighting, Rebecca basically levels your entire roster for you.
This saves hours of grind and lets you build your collection fast without burning out.
Demon Wedges
Once you start farming Demon Wedges, there’s one you need above all else: Typhon’s Prime: Serenity.
It restores 20 sanity every 3 seconds, and when you equip it on your whole team, that’s 80 sanity restored every tick.
It completely removes the early-game sanity bottleneck — you’ll be able to use skills freely instead of waiting for regeneration.
Almost every top player runs this wedge on every team. If you see it in the drop pool, farm it immediately. It makes a night-and-day difference in how fast you can fight and clear content.
Story Completion Time
Don’t worry if you’re not racing through the story. Finishing the available launch content takes about 10–12 hours at a normal pace — no skips, some exploration, a few retries.
You’ll hit around level 40 naturally by the time you’re done, which is exactly where all farming systems open up.
Take your time with it. The game doesn’t punish breaks. There’s no “energy” to waste.
Launch Day Roadmap
If you want a clear plan to follow, here’s a simple list that’ll keep you efficient and stress-free:
- Finish the Prologue and unlock Sanctuary.
- Pick your carry character (MC or Berenica).
- Push through the main story until you unlock all free characters.
- Hit level 40 by finishing the story.
- Invest everything into Rebecca for farming efficiency.
- Start doing dailies for Secret Letter Clues.
- Farm Typhon’s Prime: Serenity Demon Wedges ASAP.
- Use Rebecca to AFK farm commissions and level everyone else.
- Farm Secret Letters for the character or weapon you want next.
- Experiment with new builds once your main team is stable.
That’s the cleanest, no-fuss path to becoming fully self-sufficient as a free player.