Hurricane

Create a massive storm of wind and debris to pound your enemies to bits.

Hurricane is the Druid's level 30 Elemental skill, requiring Tornado; it unlocks nothing. It is a buff on the caster (aurastate hurricane): for 10 seconds a storm of 6 yards radius moves with you and deals cold damage and a chill to everything inside it every 0.8 seconds. The numbers that decide it are the cold per application, 202–227 at level 20, the duration, 10 seconds plus 2 per hard point in Cyclone Armor, and the cost, a flat 30 mana with no casting delay.

The numbers

• Cold damage is the EMin/EMax columns: 25–50 at level 1, then +7 a level on both ends to level 8, +10 to 16, +12 to 22, +14 to 28 and +16 past that (EMinLev1–5 and EMaxLev1–5). 94–119 at level 10, 144–169 at level 15, 202–227 at level 20, 342–367 at level 30. The Basin's formulas give the same.
• Cold length is ELen 50 frames, 2 seconds, at every level; the row has no per-level column for it.
• Radius is Param3 = 9 (aurarangecalc par3), which the tooltip prints as par3 × 2 ÷ 3 = 6 yards at every level, so it is not in the table.
• Duration is auralencalc = ln12 + Cyclone Armor hard points × Param7: Param1 250 frames ("Duration baseline"), Param2 0 a level, so 10 seconds at every level, plus Param7 50 frames, 2 seconds per hard point in Cyclone Armor. Constant without the synergy, so not in the table.
• Periodic damage delay is Param4 = 20 frames: the damage lands every 0.8 seconds, so the Basin says to multiply the displayed cold by 1.25 for cold per second, about 253–284 a second at level 20.
• Mana is a flat 30, and the row has no delay column; the Basin records the older game's 6-second global delay and none in D2R.

The damage line reads lvl, so +skills from items raise it; all three synergies read hard points only.

How it works

Hurricane is a cast on your cast rate (Casting Speed). The Basin's description: it applies cold damage and cold length every 20 frames (0.8 seconds) to targets within the radius of your current position, so the storm follows you, and casting again while it runs simply resets the duration. The damage is Cold Damage with the chill of Chill and Freeze for 2 seconds, cut by the target's Cold Resist and raised by Cold Skill Damage, see Dealing Elemental Damage. It cannot be blocked (the Basin lists it as not blockable) and rolls no attack rating. The Basin adds that in the older game it could not be cast as a werewolf or werebear.

The Basin's chill rule: the difficulty's cold-length penalty means a target stays chilled through the whole 0.8-second gap in Nightmare only if its cold resistance is 20% or less, and in Hell only if it is −67% or less; a Hell monster at 0% cold resistance is chilled 12 of every 20 frames, 60% of the time.

Synergies and +skills

Three synergies. Cyclone Armor, +2 seconds duration per level (Param7 = 50 frames, "Duration synergy", inside the duration calc). Twister and Tornado, +9% damage per level each (Param8, "Damage synergy", through EDmgSymPerCalc = (skill('Twister'.blvl) + skill('Tornado'.blvl)) × par8). All read hard points only. Hurricane's own hard points are a synergy for Cyclone Armor (+7% absorbed a point), Twister (+10% damage a point) and Tornado (+9% damage a point). The Basin's page also lists Hurricane as a synergy for Arctic Blast in the older game; the current Arctic Blast row does not read it.

Against players

A player's hit on another player is cut to 17% of its value (difficultylevels.txt PlayerDamagePercentVSPlayer) before anything else, see Player versus Player. The Basin's page says nothing more about Hurricane against players.

Build notes

• Twenty hard points in Cyclone Armor make the storm 50 seconds long for 30 mana; with no delay it is never down, and the same points are +9% each on Tornado.
• Twister and Tornado maxed are +360% on the cold, so a wind Druid's Hurricane rides on the points the build already spends.
• The chill lapses between applications in Nightmare above 20% cold resistance and in Hell above −67% by the Basin's rule, and the cold damage itself stops on cold immunes, where Tornado's physical does not.
• Six yards around you, every 0.8 seconds: it is a reason to stand in the pack, which Cyclone Armor's pool makes affordable against elemental packs.