OT0 Field Guide OT0 Field Guide

Action Skills and Mastery System Guide: Training Ground Teaching, Fees, and Best Picks in Octopath Traveler 0

Updated 2026-09 Game version 1.0.7.0 Reading time 17 min

Verified against the released game (v1.0.7.0). Where sources disagree, we say so.

Jobs define what a character is; Action Skills define what a character can borrow. Octopath Traveler 0's Mastery system lets you acquire skills as items — called Masteries — and equip them onto companions, detaching skills from the jobs that own them. Layered on top is the Training Ground in Wishvale, where your companions can teach their own skills to each other for JP fees. Together these systems are how you patch weakness-coverage holes, duplicate your best skills across the party, and turn a 35-companion roster into a genuinely custom build. This guide covers the confirmed mechanics, the economy, and a selection framework that works even where public skill data is thin.

The confirmed mechanics

  • Action Skills are equippable skills, obtained as Mastery items, and they are usable by any companion — not locked to a job or a character.
  • The Training Ground lets companions master-teach their own skills to others, charging a fee that runs from 500 to 2,500 JP per skill taught.
  • The Training Ground is a Wishvale building that also provides passive EXP/JP to assigned characters: 4 slots at base, upgrading to 8 and then 12.
  • At Training Ground Lv2, it additionally handles Ultimate Technique teaching (covered in ultimate-techniques).
  • Masteries enter your inventory from several confirmed sources: the Wishvale Shop sells Masteries and recipes (unlocked via Kindlers Ch.3 through Ludo); the Digital Deluxe edition's Deluxe Travel Provisions include 3 Action Skills; and the post-game super boss Amatsukami No Orochi drops the Dragonfire Mastery alongside a Heavenly Jewel.
  • Community databases catalog roughly 173 Action Skills in the game — the system is deep, and it is one of the areas where public documentation is still incomplete.

One honesty note before the strategy sections: our research confirms the system's structure and fee ranges, but a verified, complete list of Mastery names and effects does not exist in our sources. Rather than invent a "top ten Masteries" list, this guide gives you a selection framework built on confirmed mechanics — and tells you exactly how to evaluate any Mastery the game puts in your hands.

Prerequisites

  1. Wishvale founded and building unlocked — after the "A Flame Rekindled" task puts up your Workshop (staffed by Stia), "Rekindling the Flame Pt. 1" (invite Thyme) opens full construction.
  2. The Training Ground built — it is the home of both passive EXP/JP and master-teaching, so it belongs high in your construction order regardless of how you use Masteries.
  3. The Shop (Kindlers Ch.3, Ludo) if you want to buy Masteries rather than find them.
  4. A JP budget. Fees of 500–2,500 JP per taught skill mean serious Mastery work competes with job unlocks for your JP income — plan them together (see unlock-all-jobs for the job side of the budget).

How master-teaching actually works

The teaching flow, as confirmed:

  1. Build and staff the Training Ground.
  2. Choose a companion who knows a skill natively — their own job skills are the teaching pool.
  3. Pay the fee (500–2,500 JP, scaling with the skill) to teach that skill to another character.
  4. The learner gains the skill as an equippable Action Skill — usable regardless of their job.

Two strategic properties fall out of this design. First, your companions are the curriculum: every recruitment is also a skill-library expansion, which adds a hidden dimension to recruiting priorities — a companion whose native skills you want on three other characters is worth recruiting earlier than their combat stats suggest. Second, fees scale, so teaching has a triage problem: at up to 2,500 JP per skill, you cannot teach everything to everyone, and the selection framework below is how you decide.

The selection framework

Evaluate any Mastery or teaching decision against these four tests, in order:

Test 1: Does it close a weakness-coverage hole?

The fourteen-type weakness chart (Sword → Polearm → Dagger → Axe → Bow → Staff → Tome → Fan → Fire → Ice → Lightning → Wind → Light → Dark) is the master checklist. Lay your eight-member formation against it and find the types nobody can hit — those holes are where Masteries earn their fee first. A formation that cannot touch Tome or Fan weaknesses (the two new weapon types) has a permanent structural leak, because you never choose what a boss is weak to. Coverage Masteries are the highest-priority purchases in the system, full stop. See break-and-boost for why coverage converts directly into wins.

Test 2: Does it duplicate a skill your formation rotates around?

Some skills are so central to your game plan that one copy is a bottleneck — your best multi-hit shield-stripper, your cleanse, your key buff. Master-teaching duplicates these onto a second character, which matters doubly in OT0's row system: your two copies can sit in different front/back pairs, so the skill is available regardless of which half of the rotation is forward. Duplication Masteries are how you make a four-pair formation resilient instead of scripted-fragile.

Test 3: Does it give a back-row specialist something to matter for?

Back-row characters cannot act, but "from the back row" skills exist and check position at turn start (back-row-battle). If your formation includes characters whose main job is to charge BP and regenerate in back, equipping them with back-row-relevant Masteries converts their idle time into value. This is the most OT0-specific use of the system and the one most players discover last.

Test 4: Is the fee proportionate to the JP economy?

At 500 JP, teach freely — that is pocket change against the 2,730 JP cost of a job gate. At 2,500 JP, the skill must pass one of the three tests above decisively, because that fee is nearly a full job unlock. A useful rule: cheap Masteries for coverage, expensive Masteries only for duplication of skills you build around.

Where Masteries come from: acquisition routes

  • Wishvale Shop. Sells Masteries and recipes once unlocked (Kindlers Ch.3, Ludo); its trade slots expand 10 → 15 → 20 with upgrades, so check stock after every upgrade tier.
  • Master-teaching at the Training Ground. The renewable route — your roster is the inventory.
  • World drops and rewards. Elite enemies (52+ Menacing enemies across the world) and post-game content are the hunting grounds; the headline confirmed drop is the Dragonfire Mastery from Amatsukami No Orochi, the post-game super boss at the Cove of Clouds (reached via Garden of Sin → Skies of Vanity).
  • Digital Deluxe Travel Provisions. Three Action Skills as edition bonus — a head start, not an advantage you cannot close in-game.

Working example: patching a boss formation

Say you are preparing for a Bestower-arc boss weak to Fan and Lightning, and your formation's Fan coverage is zero — no recruited companion touches it. The Mastery workflow:

  1. Identify the hole with the weakness chart (Fan, slot 8 of 14).
  2. Find a source: check the Shop's Mastery stock, then review your roster for any companion with Fan-native skills worth master-teaching.
  3. Pay the fee on the cheapest adequate option — remember the proportionality rule.
  4. Equip it on the right character: your shield-stripping pair, specifically the member who stays front during stripping turns (back-row-battle for pairing logic).
  5. Re-verify coverage: the formation should now touch Fan; note Lightning as the next hole if unaddressed.

This loop — chart, hole, source, equip, verify — is the entire skill of the Mastery system. Run it before every major boss and the system will never surprise you.

Pitfalls

  • Spending 2,500-JP fees on skills that fail the four tests. Expensive teaching is for build-around duplication, not for filling out a collection. The JP has a competing use — job unlocks — and job unlocks usually win.
  • Ignoring the Training Ground's passive slots. The same building pays 4→8→12 characters passive EXP/JP; players who use it only for teaching leave half its value idle. Patch v1.0.7.0 raised its capacity — update your game.
  • Equipping a Mastery on the wrong half of a pair. A stripping skill belongs on the character who is front during stripping turns. Masteries do not fire from the bench; match the equipment to the rotation role.
  • Treating Masteries as endgame only. The Shop opens in the Kindlers arc's third chapter and fees start at 500 JP — coverage patching is an early-game tool that most players discover far too late.
  • Trusting incomplete wiki lists. Public Mastery databases are still being filled in; where a list conflicts with what you see in-game, believe the game — it is the only complete source that exists today.

Expected result

Run the selection framework and your formation stops having structural holes: every weakness type is attackable by someone, your build-around skills exist in duplicate across pairs, and your back-row specialists contribute even while charging. That is the Mastery system's real purpose — not new toys, but the elimination of "we simply can't hit that weakness" as a reason to lose.

Training Ground deep dive

Because every Mastery workflow runs through this building, its details are worth knowing precisely:

  • Passive slots: 4 → 8 → 12 as you upgrade. Assigned characters gain EXP/JP while you play — this is how your teaching fees get funded without grinding, and patch v1.0.7.0 (March 5, 2026) raised the building's capacity, so update before planning around old numbers.
  • Mastery teaching is available from the base building; fees run 500–2,500 JP per skill, scaling with what is being taught.
  • Lv2 adds Ultimate Technique teaching (ultimate-techniques) — one more reason the Training Ground competes for your early Radiant Cornerstones (2 for Lv2, 4 more for Lv3, farmed from the 52+ elite enemies).
  • Upgrading is therefore a three-way value decision: more passive slots, the same mastery fees, and the Ultimate tier at Lv2. For Mastery-focused players, Lv1 already does the core job; the upgrades are about everything else the building does.

The fee economy, budgeted honestly

A realistic mid-game Mastery program: two coverage patches (~500–1,000 JP each if taught cheaply, more if the skill is high-tier), one duplication of a build-around skill (assume the expensive end, 2,500 JP), and periodic Shop purchases. Call it 4,500–7,000 JP per major build revision — roughly the cost of two or three job gates (2,730 JP each). That is the honest scale of the system, and it dictates sequencing: job ladder first through your third job, then Mastery spending becomes the better marginal use of JP. Players who reverse the order end up with beautifully equipped characters and a protagonist stuck on one job.

A second budgeting wrinkle: the Training Ground's passive slots pay the characters assigned to them, so the characters you are investing Masteries into should also be the characters cycling through passive slots. Let the building fund its own students.

Native skills versus Masteries: what to teach and what to leave

Not every skill is worth propagating. Before paying a fee, ask what the native owner does that a learner cannot:

  • Teach skills whose value is positional or coverage-based — a weakness type your formation lacks, a cleanse you need on the safe pair, a back-row effect for your charging specialists. The learner gets 100% of the value.
  • Leave skills whose value is entangled with the owner's stats or role. A nuke tuned to its owner's elemental attack stat underperforms on a random learner; a skill that synergizes with the owner's native kit loses the synergy when transplanted. Our sources do not itemize which skills fall here — the in-game skill description tells you, and the fee screen tells you what it costs to find out.
  • Never teach redundancy you already own. If two formation members already cover a weakness type, a third copy is collection, not strategy.

A mid-game shopping and teaching routine

Fold Masteries into the town routine from the beginner-guide:

  1. Every Shop upgrade tier (trade slots 10 → 15 → 20), re-check Mastery stock — inventory expands with the building, and a slot that held nothing useful at Lv1 may hold exactly your missing coverage two upgrades later.
  2. Every new recruitment, open their skill list and tag anything your formation would want taught.
  3. Every boss door, run the chart-hole-source-equip-verify loop from the worked example.
  4. Every Training Ground visit, rotate passive-slot assignments toward whoever is next in the teaching queue.

Ten minutes of routine keeps the system current without dedicated farming sessions.

The coverage audit worksheet

The highest-value exercise in this whole system is a ten-minute audit you can do right now. Write the fourteen weakness types down the left side of a page — Sword, Polearm, Dagger, Axe, Bow, Staff, Tome, Fan, Fire, Ice, Lightning, Wind, Light, Dark — and your eight formation members across the top. For each member, mark the types they can hit with native skills and weapons. What remains unmarked is your hole list, and the hole list is your Mastery shopping list, in priority order.

Three refinements that make the audit honest:

  • Count pairs, not just people. A type covered only by two members of the same front/back pair is half-covered: when that pair is doing something else (rotating, frozen after a boost), the coverage vanishes. Aim for every type to be attackable by members of at least two different pairs.
  • Weight by position in the reveal order. Holes low in the fixed order (Sword first, Dark last) are revealed later, which means more probing turns wasted mid-fight. A Tome or Fan hole costs you more time than a Sword hole.
  • Re-run the audit after every major recruitment and every job unlock. The hole list shrinks as your roster grows; Masteries should always target whatever survives.

Teaching priorities by companion type

Since companions are the curriculum, some categories of teacher deserve priority at the Training Ground:

  • Early guaranteed recruits (the Kindlers track: Phenn, Ludo, Laurana) — you will own them longest, so their teachable skills are available from the moment the building stands. Audit them first.
  • The eight OT1 legacy companions (Olberic, Alfyn, H'aanit, Tressa, Therion, Primrose, Cyrus, Ophilia) — their series-established kits are broad, and several are mid-game recruits, which makes them the backbone of a Master of All-era teaching wave.
  • Exclusive-job characters (Architect Stia, Cait Scholar Isla, the Bestower of All recruits) — their kits exist nowhere else on the roster. Where their skills are teachable, they are by definition un-duplicable through any other route; where they are not teachable, that exclusivity argues for fielding the character rather than trying to replicate them.
  • Late recruits with named Ultimates (Pius, Saoirse, Carinda, Xerc) — evaluate their teachable skills at recruitment, but remember their Ultimates (ultimate-techniques) are often the real prize, and Ultimates live on the Lv2 teaching track, not the Mastery one.

Mastery economics: when the Shop beats teaching

The two acquisition routes have different price shapes. Master-teaching scales from 500 to 2,500 JP per skill; the Shop charges Leaves and expands its stock with upgrades (trade slots 10 → 15 → 20). The practical rule: JP and Leaves are not interchangeable — spend whichever is cheaper for you right now. Early, when JP is feeding the job ladder and Leaves flow from Merchant passives and Cait statues, Shop Masteries are the bargain. Late, when the job ladder is finished and JP income outpaces anything to spend it on, the 2,500-JP teaching tier stops being intimidating. Players who understand this stop asking "can I afford this Mastery" and start asking "which currency should this Mastery cost me."

How do Masteries interact with Boost and Break? Action Skills follow the same combat rules as native skills: Boost multiplies them (up to 3 BP per action), and a Mastery-granted attack that matches an enemy weakness strips Shield Points exactly like a native one. That equivalence is the entire point of the system — a taught coverage skill is indistinguishable from a born one the moment it lands. It is also why coverage Masteries outrank luxury picks: they plug directly into the game's core loop rather than sitting beside it.

Should I spread Masteries wide or stack them on one character? Wide, almost always. The system's purpose is coverage and duplication across pairs — a single stacked character is one swap away from taking all your investment to the back row. The exception is a dedicated back-row specialist, whose entire job is carrying the passive-value picks while charging BP.

Troubleshooting

I paid the fee but the skill never shows up in battle. Action Skills are equippable — teaching adds the skill to the learner's library, but it does nothing until you equip it in their loadout. Check the equipment screen first; this is the most common "bug report" the system produces, and it is never a bug.

The teacher I want does not offer the skill I need. The teaching pool is each companion's own native job skills — if the teacher has not learned the skill themselves yet, it cannot be taught. Fund the teacher's JP purchase first, then pay the teaching fee. This also means teaching chains do not exist: a learner who received a skill through teaching does not become a new source for it.

The 2,500-JP fee is beyond my budget right now. Then it is correctly beyond your budget — expensive teaching is for build-around duplication, and the JP has a competing use in the job ladder (2,730 JP per gate). Park the plan, cycle the intended learner through the Training Ground's passive EXP/JP slots so the building helps fund its own student, and revisit after your next job unlock.

The Shop sells no Masteries. Two gates to check: the Shop itself requires Kindlers Ch.3 (Ludo's line), and its stock scales with upgrade tiers (trade slots 10 → 15 → 20). A Lv1 Shop is a partial catalog — re-check after every upgrade before concluding a Mastery does not exist for sale.

I taught a coverage skill and the boss still walls me. Coverage is necessary, not sufficient: the equipped character must also be front during stripping turns. A perfect Mastery on the wrong half of a front/back pair spends the fight in the back row, where no skill fires. Match the equipment to the rotation role.

Can a taught skill be passed on to a third character? The confirmed wording is that companions master-teach their own skills — so no: treat every native owner as the single source for their skills, and budget one fee per intended learner. If a skill is party-critical, the fee for duplicating it twice is part of the build's real cost.

Should Masteries go on my front-liners or my back-row specialists? Both, but differently: active coverage and stripping skills belong on whoever is front during those turns, while back-row specialists (who cannot act but charge BP and regenerate) are the natural carriers for any "from the back row" effects — those check position at turn start, so equip them on the character whose job is to be in back.

Action Skills and Mastery FAQ

Do Masteries work on the protagonist? Confirmed sources describe Action Skills as equippable by "any companion"; whether the protagonist is included in that wording is not something our ledger pins down. Check in-game — the equipment screen answers it instantly.

Can a taught skill be removed or moved? Action Skills are equippable by design, so treat loadouts as flexible. What is permanent is the JP fee — spend it on skills you will actually equip.

Is the Digital Deluxe head start worth buying for? The Deluxe Travel Provisions include 3 Action Skills, 8 M-nuts, 5 town decorations, and a digital art book. It is a convenience package; nothing in it is exclusive power you cannot out-earn in-game. Buy it for the art book.

What is the single best Mastery in the game? No verified complete list exists in our sources, so any site claiming one is guessing. The confirmed headline drop is the Dragonfire Mastery from Amatsukami No Orochi — a post-game super-boss reward, which is the game's own statement about what it considers top-tier.