BRIGANDINE ABYSS Missables — 100% Completion & Before-Final-Battle Checklist

Short answer (labels you should use while planning):

• Confirmed run-sensitive: the platform lists explicitly require you to “Control 10 or more bases in one playthrough” and to “Defend against at least 3 invasions from other factions in one playthrough.” Those can be missed for that playthrough.
• Reversible / repeatable: ordinary first-action, combat, quest, recruitment, equipment, and progression goals are not marked missable on the current platform surfaces. Whether progress persists across campaigns is Not yet verified.
• Requires another campaign: each named Story clear and many Mission Mode milestones require separate campaign clears.
• Not yet verified: cross-save accumulation, post-campaign Gallery repair, weapon/character/monster acquisition dependencies, save-point behavior, class/branch reversibility, and any hard point of no return.

Do not conflate campaign-specific goals with permanent missability. The platform surfaces do not label trophies as missable — that shows the surfaces don’t mark missables, not that they are impossible.

[IMAGE: Save slots and title-screen reminder]

Use this decision order. For each item you should answer “Check now?” and “What is actually known?”

• Check now? Yes if you need the in-run clear credited toward a Story or Mission milestone.
• What is actually known? Each named Story clear and each Mission Mode milestone (3, 8, 15, all factions) is a separate required clear. These are campaign-specific: completing Gran Dragnica’s Story does not complete Scarlet Will’s Story for you. Whether these counters stack across saves or systems is Not yet verified. See the Story vs Mission planning table below. For full trophy checklists and per-trophy names, go to the Trophy & Achievement Guide.

• Check now? Yes — these are explicitly run-sensitive on the platform surfaces.
• What is actually known? Two platform-listed requirements use the exact phrase “in one playthrough”: Control 10 or more bases in one playthrough; Defend against at least 3 invasions from other factions in one playthrough. These are Confirmed run-sensitive. Whether missing them permanently locks anything is Not yet verified.

• Check now? If you need a character unlocked for gallery or a class/quest, check recruitment options before finishing.
• What is actually known? The official materials expose the roster; the platform requirement includes completing the Character List. Hidden or recruitable character acquisition timing is Not yet verified. For details and guidance, see Hidden Characters and Characters.

• Check now? If a Mission objective or gallery entry requires specific monsters, check Monster availability during the run.
• What is actually known? System pages confirm stronghold monster contracts and Mission Mode “Collect Monsters” objectives, but the full roster, quest-only acquisitions, and whether monster entries become unavailable after a campaign are Not yet verified. See Best Monsters and Monster List.

• Check now? If you need a weapon to finish a quest or gallery entry, check merchants and merchant schedules in-run.
• What is actually known? Traveling Merchant(s) sell weapons and armor per the official System page. Whether the Traveling Merchant is the sole source for every weapon or whether some are quest-only is Not yet verified. For broader equipment help, see Equipment.

• Check now? If you are tracking the 100-quest long-term target, check quest progress during the run and do not assume it carries across campaigns.
• What is actually known? The 100-quest milestone is a long-term target listed on platform surfaces. Official systems confirm Explorations and quests return resources and experience. Whether quest counts carry across saves/campaigns is Not yet verified. See Quests & Training.

• Check now? Yes if finishing the campaign will trigger credits and you want to confirm which gallery entries unlock on completion.
• What is actually known? Platform lists include Faction, Character, Battle, Atlas of Meltitea, and Mercenary/Monster Lists as required. Some players report gallery lore becomes visible after credits, but that is player observation and Not yet verified as universal. If you want to test post-credits gallery behavior while preserving your run, keep a backup save (see below).

• Check now? If you need a unit, skill, or base at max for a trophy, check the specific progress bars in-run.
• What is actually known? Platform lists include maximum unit level, maximum skill level, and maximum base level. These are long-term progression goals; whether caps or progress persist across saves is Not yet verified.

• Check now? Yes — confirm run-sensitive items and gallery entries before triggering campaign-ending credits if preservation matters to you.
• What is actually known? Players report the game returns to the title screen after credits and some gallery changes may happen then; this is an observation, not a verified cross-save rule. The official surfaces confirm manual/anytime saving but do not establish a universal point of no return; details about forced checkpoints or required backup slots are Not yet verified.

• Control 10 or more bases in one playthrough. (platform requirement text — Confirmed run-sensitive)
• Defend against at least 3 invasions from other factions in one playthrough. (platform requirement text — Confirmed run-sensitive)

• Fill all equipment slots for a leader unit. (Hidden on Steam; published on current PS5 surface)
• Defeat 3 enemies with a single area attack. (Hidden on Steam; published on current PS5 surface)
• Defeat an enemy using a leader unit who has a monster rallied. (Hidden on Steam; published on current PS5 surface)

Note: The platform surfaces list 39 total achievements/trophies. The site’s full 39-item checklist is available at /trophy-guide/ — this Missables page focuses on run-sensitive planning, not reproducing the entire checklist.

• Check now? Yes if specific gallery entries are required for progression or trophies you want to secure in this run.
• What is actually known? Platform inventories include multiple gallery lists as achievement requirements. Some players report that gallery content updates after a campaign ends, but this is player observation and Not yet verified. If you want to be cautious, verify gallery entries while still in the campaign and use a backup save if your platform supports it.

• Weapons: Traveling Merchant(s) sell weapons and armor per the official System page. Whether every weapon is merchant-sourced or some are quest-only is Not yet verified. If a specific weapon is required for a trophy or gallery entry, prioritize acquiring it during the run. See Equipment for broader help.

• Characters: The official materials expose the roster and the platform requires completing the Character List, but hidden/recruitable acquisition timing is Not yet verified. If a character matters to your completion plan, check recruitment options before ending the run; do not treat that as proof of permanent missability. See Hidden Characters and Characters.

• Monsters: Stronghold monster contracts and Mission Mode “Collect Monsters” are confirmed systems. Whether any monster becomes unattainable after ending a campaign is Not yet verified. If a monster matters to your gallery or trophy plan, check its availability during the campaign. See Best Monsters and Monster List.

Keep a backup before approaching campaign completion if your platform supports separate manual save slots and you want to preserve the current state while checking Gallery, collection, or final-battle behavior. This is a prudent option, not proof that the game has an irreversible final checkpoint. Neither the official Steam nor PlayStation surfaces establishes a universal hard point of no return; manual saving / Save Anytime is documented but not a guarantee of cross-save persistence.

• This page explains what to track during a run and what is Confirmed run-sensitive vs Not yet verified. For the full 39-item trophy and achievement checklist, see the Trophy & Achievement Guide.

• Difficulty and seasons: Difficulty & 30 Seasons
• Faction planning: Factions
• Organization Phase (exploration, recruitment, merchants): Organization Phase
• Walkthrough and step planning: Walkthrough
• Equipment: Equipment
• Characters and hidden recruits: Characters and Hidden Characters
• Monsters and best squads: Best Monsters and Monster List
• Quests and training: Quests & Training

This page follows the official system and product surfaces (NIS America, Happinet, Steam, PlayStation) and current platform achievement/trophy listings. Player reports exist but are marked Not yet verified where they cannot be confirmed by official surfaces. For the exact achievement/trophy text and the complete 39-item list, see the Trophy & Achievement Guide.