Frost Nova

Creates an expanding ring of ice that damages and slows all nearby enemies.

Frost Nova is a Sorceress Cold skill (level 6, no prerequisite) and, with Glacial Spike, the prerequisite of Blizzard. It is the cold twin of Nova: a ring of missiles that expands from the Sorceress and hits everything it crosses, damaging and chilling it. Two numbers decide it: the damage, 75–86 at level 20 before synergies, and the chill, 27 seconds at level 20 in Normal.

The numbers

The damage comes from EMin 4 and EMax 8 with HitShift 7, which halves them: 2–4 at level 1. The minimum then grows +3 a level to level 8, +4 to 16, +5 to 22, +6 to 28 and +7 a level past that; the maximum grows +3.5, +4.5, +5.5, +6.5 and +7.5 over the same brackets. That is 31–37 at level 10, 75–86 at level 20 and 135–151 at level 30. The line reads lvl, so +skills count.

The cold length is ELen 200 frames plus 25 a level (ELevLen1–3 are all 25), at 25 frames a second: 8 seconds at level 1 and 1 second more a level, 17 at level 10, 27 at level 20, 37 at level 30. It also reads lvl.

Mana is 9 at level 1 and 1 more a level (mana 9, lvlmana 1, manashift 8): 18 at level 10, 28 at level 20, 38 at level 30.

How it works

Frost Nova fires a ring of "frostnova" missiles outward from the Sorceress; the Basin's page classes it as a medium-range multi-missile cast and says a target is damaged and chilled if any part of it is within about 8 yards of the caster (or of the target, when the nova is cast by an item's chance to cast on striking). The ring has no attack roll: every monster it crosses is hit. It is cold damage, reduced by the target's cold resistance, see Dealing Elemental Damage and Resistances and Immunities, and it is cast at casting speed.

Every hit chills: the target is slowed for the cold length above, by the monster's own cold-effect figure, and the length is divided in Nightmare and Hell, see Chill and Freeze. The Basin's page gives the nova a next-hit delay of 4 frames, so a target hit by one missile of the ring cannot be hit again by another within those frames.

Frost Nova's chill is a slow, not a freeze; the monsters around you keep swinging, only slower, by the figure on each monster's page.

Synergies and +skills

• Blizzard: +10% cold damage per level and Frozen Orb: +10% cold damage per level (skills.txt Param8 = 10; the calc reads each skill's blvl, hard points only).
• Frost Nova in turn feeds Ice Bolt at +15% a hard point; it feeds nothing else.
• +skills raise the damage and the cold length (lvl); the percentages do not move with +skills.
• Cold Mastery lowers the target's cold resistance and so raises what lands.

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 gives no other rule for Frost Nova against players.

Build notes

• On a Blizzard or Frozen Orb Sorceress the hard points in those skills are already Frost Nova's synergies: one point here with 20 in each is a +400% ring that chills for 8 seconds plus +skills.
• The chill, 27 seconds at level 20, is what the skill is for: the damage at that level is below every cold attack but Ice Bolt, and the mana (28) is the same as Chain Lightning's.
• Each hard point is also +15% to Ice Bolt, the only skill it feeds.