Dot Abyss Formation Guide

You start with three tutorial units and grow toward a full ten-slot roster through gacha, beginner missions and idle exploration. Formation slots themselves unlock with account level — you do not need a special item. The bottleneck is characters, not slots.

• Tutorial redraw + launch tickets: aim for one SSR Back core (Nina, Vira, or Electra).
• Beginner mission day 7: Select SSR Box — Hymena is the safest F2P front pick.
• SR units from the standard pool (Rosa, etc.) fill Front gaps until SSR tanks arrive.
• Cross-check pulls against the tier list before investing materials.

The standard competitive spread is Front4 / Back3 / Assist3 — four tanks and bruisers absorb hits, three Back attackers deal damage, three Assists buff, heal and operate turrets. Total: ten units, matching defense and Deep Abyss caps.

• Front4 — HP, defense and status resist; at least one self-heal or counter tank.
• Back3 — your DPS triangle; mix elements so one Calamity counter always exists.
• Assist3 — one healer (mandatory), one Impact/Passion battery, one turret or team buffer.
• Passion (情熱) units self-charge by acting; Impact (衝撃) units need stacks from hits, dodges or allies.

Open formation from the Frontline Base battle menu or any defense / exploration deploy screen. Tabs switch between Front, Back and Assist rows; drag units into slots or tap auto-fill (which you should overwrite with a real plan).

• Preset slots save up to three named formations — one for story defense, one for exploration farm, one for Deep Abyss locks.
• The emblem icon on each portrait shows Passion vs Impact — sort by emblem when building pairs.
• Turret icons appear only on Assist slots during defense deployment.
• Locked Deep Abyss runs grey out the edit button — finalize on the Deep Abyss prep screen before spending a Gate Key.

A healer is required in every serious formation — not optional luxury. Front4 delays collapse; a healer Assist actually reverses it. Most F2P failures come from running Back3 + damage Assists with zero recovery.

• Reserve Assist slot 1 for healing or shielding — even a built SR support outperforms a third DPS Assist on long waves.
• Front units with self-heal (Wendy) or lifesteal gear reduce healer load but do not replace one.
• Impact batteries belong in Assist if your Back spenders are hungry — Pico is the premium example.
• For Deep Abyss, healing Assists matter more because erosion outpaces passive regen.

A complete formation covers all three roles: soak, spike and sustain. Use these templates as starting points — swap one slot for element counters per Calamity.

Optimize emblem synergy last — after you have a healer and a stable Front4. The highest-ROI pairing is one Impact generator feeding two spenders:

• Front: Wendy (Impact on hit) or Nina (Impact on dodge) — pick one generator, not both.
• Back: Electra + Vira as spenders; third Back is element flex from the tier list.
• Assist: Pico (Impact battery + skill amp) + healer + turret operator for defense.
• F2P without Pico: use an SR Impact support and accept slower cycles — still bring the healer.