Thrash from Scratch — Base Skill Multipliers

1. The Base Damage Equation

Thrash damage per hit follows the standard D4 per-hit formula (see buildcrafting/damage-buckets.md for the bucket definitions):

Hit = WeaponDmg× SkillScalar # Thrash-specific, see below × MainStat # Dex/800 for Spiritborn× (1 + Additive%) # pooled +__% bucket× (1 + x_Crit%) # pooled %x Crit bucket× (1 + x_Vuln%) # pooled %x Vuln bucket× (1 + x_DoT%) # pooled %x DoT bucket× (1 + x_AllOrEle%) # pooled %x All+Element bucket× Π(1 + x_Global_i%) # independent %[x] globals, multiplied separately × CritMult # if hit crits × DamageTakenMult # enemy-side, constant for build math

Where for Thrash the SkillScalar comes from the per-hit formulas in the power definition. The two interesting payloads are the 1st/2nd hit (single slash) and the 3rd hit (the salvo).

1a. The skill scalar values (from d4data)

1st & 2nd attack: SF_1 = 0.40 × Table(34, sLevel) — one slash, single hit.
3rd attack: ~10 ticks of SF_5 = SF_1 × 3.5/10 each — salvo of small hits, totalling ~3.5× a single slash over the full 3rd-attack window.

Net intrinsic ratio: the 3rd attack carries about 3.5× the damage of one regular slash before any modifiers, and is the entire reason every Thrash build builds around landing 3rd hits as fast and as often as possible.

2. The Five Skill-Tree Upgrades (Mods)

Thrash has five upgrade slots on the skill tree. After the Lord of Hatred restructure, any three of these can be slotted in any combination — the old “Enhanced / Brawling / Natural” gating is gone. The damage-meaningful ones, in descending impact:

#	Source (Mod)	Bucket	Effect & numbers
1	Ramping Damage (Mod6)	independent `%[x]`	Each hit of Thrash increases the damage that enemy takes from Thrash by +35%[x] per stack (SF_31 = 0.35), stacking up to 20 stacks (SF_34 = 20 ÷ SF_31) → +700%[x] at cap (×8.0 multiplier). This is the single biggest multiplier on Thrash and sits in its own independent global bucket.
2	3rd-hit salvo (innate, not a mod)	pre-multiplier (more hits)	Baked into the skill itself, no slot cost. ~10 hits at `SF_5 = SF_1 × 0.35` each → ~3.5× total damage per 3rd attack versus a single slash. Every other Thrash multiplier rides on top of this.
3	Storm Conjurer (Mod3)	tag conversion (not a number)	Thrash becomes an Eagle skill dealing Lightning damage, and the 3rd attack also spawns a moving Spirit Storm that Sparks enemies for a Lightning DoT (`dot:LIGHTNING_DOT`). Numerically zero by itself, but unlocks the entire Eagle/Lightning multiplier pool (Sky-hall aspects, Lightning `%x` globals, Eagle-tagged paragon nodes, Storm Feathers Vulnerable application, etc.). Dominant choice for damage builds.
4	Wanton Rampage (Mod4)	independent `%[x]` + chance proc	1st & 2nd attacks have a 15% chance (SF_26 = 0.15) to also unleash the 3rd attack, which is 30% larger (SF_27 = 0.3) and deals +50%[x] increased damage (SF_18 = 0.5). Effectively raises the average frequency of 3rd-hit salvos by ~15% per non-3rd cast, plus a flat +50%[x] on those salvos.
5	Crashing and Thrashing (Mod1)	independent `%[x]`	3rd attack deals +50%[x] increased damage (SF_33, same magnitude as SF_18) and Thrash continues to unleash 3rd attacks if recast within 2.75×SF_15 ≈ 4.8s (SF_4). Turns the 3rd attack into a sustained mode rather than a 1–2–3 cycle.
6	Ferocity (Mod2)	resource gain (not a damage multiplier on its own)	3rd attack grants 10 stacks of Ferocity (SF_19 = 10). Damage value depends on what Ferocity is doing in your build (max-stack-scaling aspects, Glynn’s Anvil Resolve interactions, etc.). Zero damage by itself but a build-enabler.
7	Vigor Generation (Mod0)	resource gain	Killing an enemy empowers next Thrash to generate extra Vigor, stacking up to 5 casts. Pure resource lever — useful for Vigor-spender hybrids, dead for pure Thrash spam where Vigor isn’t the bottleneck.
8	Cooldown Reduction (Mod5)	indirect (CDR)	Each hit of Thrash has a 10% chance (SF_30 = 0.1) to reduce an active cooldown by 1 second (SF_32 = 1). No direct damage, but pairs with cooldown-gated multipliers (Concussive Stomp, Counterattack, Armored Hide uptime).

HEADLINE

Ramping Damage is the single biggest base multiplier on Thrash — +700%[x] at 20 stacks, in its own independent global bucket. Second-biggest is the intrinsic 3rd-hit salvo (~3.5× per cycle). Storm Conjurer isn’t a number but a tag-conversion that opens the entire Eagle/Lightning multiplier pool, which is why it’s the dominant damage-mode pick. Wanton Rampage and Crashing and Thrashing are both +50%[x] sources stacking on top.

3. What’s NOT on This Page (yet)

Everything below is downstream of the base skill and will be layered on in subsequent passes as the new build takes shape:

Spirit Hall choice (Primary/Secondary) — Jaguar primary unlocks Ferocity scaling, Eagle primary applies Vulnerable via Storm Feathers, Gorilla primary lets Thrash benefit from Resolve / Barrier interactions.
Class passives (Focal Point, Imbued Strikes, Endurance, Skin of Glass, etc.) — several gate independent %[x] lines and Ferocity/Resolve caps.
Paragon board legendary nodes — usually the second-largest %[x] source after gear.
Aspects & uniques — the chassis. See Global Multipliers Catalog for the full Spiritborn %[x] pool.
Glyphs — Exploit, Talon, Hubris, Wildfire, Fester etc. add Crit-bucket and independent globals once paragon comes online.

4. Source Files

Power definition: d4data/json/base/meta/Power/Spiritborn_Jaguar_Basic.pow.json — ptScriptFormulas at line 2269, payload definitions immediately after.
Tooltip strings: d4data/json/enUS_Text/meta/StringList/Power_Spiritborn_Jaguar_Basic.stl.json — name “Thrash”, desc + 6 Mod_Description entries (Mod0–Mod6).
Bucket rules: buildcrafting/damage-buckets.md — source of truth for the per-hit formula and pooled/independent classification.
Marginal-gain model: buildcrafting/damage-optimization-model.md — simulator-facing math for layering build pieces on top of this base.