# PoE2 build-making primer for agents You may be new to Path of Exile 2. This is the minimum game knowledge needed to author a COHERENT build here, beyond what the data files give you. Everything below is stable game design, not patch numbers. ## What a build is A build = class + ascendancy + a passive-tree route + skill gems with supports + gear direction. Coherence comes from ONE primary damage skill, ONE main damage type/theme, and defences appropriate to the class's side of the tree. ## Point budgets - Passive points: ~99 at endgame (level ≈ points+1). A leveling guide targets 40-70; use nodes.json `cost` values to stay in budget. - Ascendancy points: 8 total (earned in 2-point chunks from trials). That's 3-4 asc_notables — pick the 2 that define the archetype first. - Weapon-set points: up to 24 bonus passive points that only apply while a specific weapon set (1 or 2) is active. They are NOT all available from level 1 — they are earned gradually from quest rewards as the character levels toward 100, so a low-level capture has few or none. Some ascendancy nodes also change this economy — Witch Hunter's Weapon Master reads "100 Passive Skill Points become Weapon Set Skill Points": it raises the weapon-set point cap by 100, meaning effectively ALL of your regular passive points can also be mirrored into per-set allocations. A target may be tagged {"node": ..., "set": "set1"|"set2"} to allocate it in one set only, and a skill may be bound with {"gem": ..., "set": "set1"|"set2"}. THE DECISION RULE — use weapon-set points when the build has two MODES; skip them when it has one. The test: would any node be dead weight half the time? Then it belongs to a set. Worked patterns: - Slow heavy weapon in one set (scale raw damage — speed is wasted on it), fast weapon in the other (scale attack/cast speed). - Clear mode vs boss mode: projectile/chain notables in set1 for mapping, single-target/mark notables in set2 for bosses. - Attack set vs defence set: damage notables swap out for block/shield notables while "Raise Shield"-style skills are up. The craft: bind each mode's SKILL to its set, tag that mode's notables the same set, and keep set-tagged nodes ADJACENT to paths you already walk (travel still costs main points — the set point only pays for the destination). Each set point is nearly free power for its mode: a two-mode build that ignores them leaves up to 24 points on the table. Validate reports per-capture weapon_set_points {set1, set2, used, cap} so leveling captures can't overspend points not yet earned. ## The tree's geography (matters for cost) Damage/attack nodes cluster by theme near the classes that use them: melee/armour south-west (Warrior), bow/evasion east (Ranger/Huntress), spell/minion/ES north (Witch/Sorceress), crit/speed north-east (Monk), hybrid south (Mercenary/Duelist region), nature/shapeshift north-west (Druid). Cross-tree targets are EXPENSIVE: prefer targets whose `cost` for your class is under ~25, and cluster targets so paths share travel. ## Defence layers — every build needs a survival plan A build that is all damage does not survive. Commit to ONE primary defensive layer (sometimes a hybrid pair) plus life — deliberately, in the plan, with passives spent on it. The layer also DICTATES ATTRIBUTES: armour gear requires Strength, evasion gear Dexterity, energy-shield gear Intelligence, hybrid bases a mix (str/dex, dex/int, str/int). Your skills' attribute needs, your class's tree region, and your defensive layer should therefore agree — that alignment is usually what makes one layer the logically sound choice for a given build type: - Armour (phys mitigation) — str gear, Warrior region. Pairs with life, block (shield), stun threshold. Weak vs elemental — cap resistances on gear. - Evasion / Deflection (avoid or deflect hits) — dex gear, Ranger/Huntress/Monk region. Strong vs attacks, weaker vs many spells; pair with acrobatic-style keystones and a recovery source. - Energy Shield (a second, recharging pool) — int gear, Witch/Sorceress region. Watch for "ES does not recharge" downsides on keystones. - Mana as a layer — Mind-over-Matter-style nodes redirect a share of damage to mana; with strong mana regen a caster can treat a deep pool as extra life. Only works if casting isn't consuming the whole pool. - Ward / runic ward and similar flat-absorb layers (mostly gear/runes) — flat per-hit absorption; effective at low investment, needs upkeep to stay relevant. - Hybrids (armour+evasion, evasion+ES, armour+ES) are legitimate — they match hybrid gear bases and split-attribute builds. - Universal, regardless of layer: maximum Life nodes (~30% of points is normal), capped elemental resistances (mostly gear), and ONE recovery mechanism (regen, leech, or flask-centric nodes). State the chosen layer(s) in the build's notes so the user knows the survival plan — e.g. "defence: evasion + acrobatics, life on every cluster, recovery via leech". ## Skills & supports - One 5-support "main skill" carries damage; 1-3 utility skills (a curse, a movement skill, a buff/herald) take the rest. - SPIRIT — the most-skipped ingredient in agent builds, and one of the most important in real ones. Spirit is PoE2's reservation resource: persistent buffs (gems tagged HasReservation — heralds, auras, Grim Feast-style effects) stay on permanently and reserve it. The base pool is quest-earned: +30 (Act 1 boss), +30 (Act 3), +40 (post-Act-4 interlude) = 100; read the conservative per-level schedule and every gem's reservation cost from /assets/agent/spirit.json. A typical real build reserves 60-100 spirit on 1-3 persistent buffs — if your plan reserves zero, ask yourself why. SUPPORTS MULTIPLY RESERVATIONS: each support's cost_multiplier/100 compounds (spirit.json support_cost_multipliers), so a heavily-supported herald can cost half again its base — a classic overspend trap. Gear extends the pool: sceptres carry exact base Spirit (granted_skills.json `bases`), +Spirit uniques count at their low roll; minion builds live and die on it. Validate reports spirit.{reserved, base_available, gear_bonus} per capture and warns (not errors) on overspend beyond base+gear. - ITEM-GRANTED SKILLS: uniques and base items grant skills while equipped (/assets/agent/granted_skills.json, `uniques` + `bases`). Sceptres are the famous case — each grants its aura/minion skill AND exactly 100 Spirit; wands and staves grant their attack spell. Free: no gem slot, and supports socket into them at no gem cost (2 sockets at granted level 1, 3 at 10, 4 at 15, 5 at 20 — spirit.json granted_skill_sockets). If your gear names one, build around it instead of re-adding it to skills[]. - Supports must be type-compatible (the require/exclude data) AND thematically sensible: more-damage supports on the main skill, duration/area/utility on utility skills. Each support once per build. - Damage-over-time skills don't crit; attack skills scale with weapon; spells scale with gem level — pick passives accordingly. ## Jewels — sockets are nodes, radius is position The tree has jewel SOCKETS (19 of them). A jewel does nothing until its socket node is allocated — pathing there costs points like any node, so a socket is only worth it when it's near your route. Send jewels as gear entries: {"slot":"jewel", "base":"Time-Lost Ruby", "mods":[…], "socket": }, and put the same node id in targets. Radius jewels (Time-Lost bases, Timeless uniques) buff passives around the socket — pick the socket whose radius already covers notables you allocated (validate reports notables_in_radius per jewel; jewels.json has the per-socket lists to plan with). Plain jewels (Ruby/Emerald/…) are position-blind: nearest cheap socket wins. ## Leveling realism — captures must be obtainable at their level Nobody has an endgame setup in Act 1. Each capture's skills and gear must be plausible AT ITS LEVEL: - Gems: skill_catalogue's `req_level` is when a gem becomes obtainable — don't put Comet (req 42) in a level-22 capture. Gem level rises with you: keep `level` ≤ roughly the capture level minus the gem's req_level (and never above natural_max_level). Mana costs grow with gem level — an early capture often runs a LOWER gem level than the maximum on purpose. - Supports: early captures realistically run 1-3 supports on the main skill; the full 5-support setup belongs in maps-level captures. Add supports capture by capture as they'd be acquired. - Gear: bases.json `lvl` is the drop level — early captures use low-tier bases with 1-2 mods ("Rare Cloaked Mail, +life +res"), endgame captures the expert tiers with 3-4 mods. Snapshot the tier progression the same way you snapshot gems. - /agent/validate checks all of this per capture (gem req_level vs capture level, gem level vs character level, base drop level). ## Gear direction (what to write in gear[]) Uniques from item_catalogue (exact names) for the slots that define the build — usually the weapon and one or two key items. Uniques ARE their rarity — never give a unique a rarity or a mods list. For every OTHER slot, don't hand-wave "any rare with ES": pick a real base from /assets/agent/bases.json whose defence type and attribute requirements match the build's layer (pure-es body for an int caster, ar/ev hybrid for str/dex), then spec {base, rarity, mods} with the 2-4 mods that matter most, most-important first. That's the difference between a build guide and a shrug. Copy mod lines from /assets/agent/mods.json — each family has `text` (the real rolled form, e.g. "+(10-214) to maximum Life") and `slots` (the spawn tags gating where it rolls: body_armour, int_armour, mace, ring…). A mod whose slots don't match the base can't roll on it. Rarity follows mod count: an item with no mods is normal, 1-2 mods is magic, more than two is rare. Stating "rare" with only the 2 priority mods listed is fine — the floor is what's enforced, not the ceiling. ## Archetype cheat sheet - Melee bruiser (Warrior/Titan): mace + shield, armour+life+stun nodes, Slam skills, totems for extra damage. - Bow crit (Ranger/Deadeye, Huntress/Amazon): evasion+crit+projectile nodes, Lightning Arrow / gas arrow style mains. - Caster (Sorceress/Stormweaver, Witch): ES+spell damage+cast speed, one element, exposure/penetration supports. - Minions (Witch/Infernalist or Lich): Spirit stacking, minion life/damage nodes, your own damage barely matters. - Trigger/DoT/hybrids exist — only attempt if the user asks. ## Common agent mistakes (from real audits) - Picking notables on the far side of the tree (check `cost`). - Reusing the same support gem in two skills (once per character). - Guessing community gem names — supports are tiered ("Multishot I"); always copy names from skill_catalogue. - Forgetting Life: a build with 15 damage notables and no life dies in act 2. ~1 life/defence node per 2 damage nodes is a sane ratio. - Spirit-reserving more than the build can have. Validate before delivering: GET /agent/validate?plan= returns resolved targets, point totals, and gem compatibility problems.