Static Field

Creates an electrical field that reduces life of all nearby enemies.

Static Field is a Sorceress Lightning skill (level 6, no prerequisite) and the prerequisite of Nova. It has no damage range: every cast takes 25% of the current life of every enemy within its radius, for a flat 9 mana. The only number that grows with level is the radius, 3.33 yards at level 1 and 16 yards at level 20.

The numbers

The radius is ln12, Param1 5 (the table's "Radius baseline") plus Param2 1 a level, shown in yards as × 2 ÷ 3: 6 yards at level 5, 9.33 at level 10, 16 at level 20, 22.67 at level 30. It reads lvl, so +skills widen it.

Two tooltip lines never change and are left out of the table: the mana, 9 at every level (mana 9, lvlmana 0, manashift 8), and "Weakens Enemies by 25%", which is Param4 (the table's "HP % Damage", also calc1). Param3, the "Minimum Damage value" (calc2), is 0.

How it works

Static Field is a radial cast around the Sorceress (aurarangecalc ln12) with no missile and no attack roll: everything within the radius is hit. The Basin's page gives the rule: each cast reduces the target's current life by 25%, unless the target is already below 33% life in Nightmare or 50% life in Hell, where the skill stops applying (the lightning-damage animation no longer shows on such a target). The damage is a percentage of the target's final life, not its base life, so each cast takes less than the last.

It is lightning damage, and the target's lightning resistance reduces it like any other, see Resistances and Immunities: the Basin's page says 50% Lightning Resist halves the cut to 12.5% of current life. Two things do not help: +% Lightning Skill Damage from Lightning Mastery and items does not increase the cut at all, and Lower Resist or Conviction that push the resistance below 0% do not increase it either, though they do stop a positive resistance from reducing it. What does increase it is -% Enemy Lightning Resistance Reduction from items, which the Basin says is applied after Lower Resist and Conviction and can take the resistance below zero: -100% against a 0% target doubles the cut to 50% of current life. The Basin gives an approximation for the mixed case, with E the item's -% enemy lightning resistance and R the resistance after Lower Resist and Conviction:

cut % = 25 × (1 + min(E ÷ 100, D) × √D), where D = max(0, (100 − R) ÷ 100)

With no resistance reduction the floors are the ceiling: in Hell a target can only be brought to 50% life by Static Field, and the rest is for other skills.

Synergies and +skills

Static Field has no synergies. It is the synergy source for Nova (+5% lightning damage a hard point) and for Thunder Storm (Thunder Storm), both reading blvl. Its own radius reads lvl, so +skills from gear widen it without a hard point spent.

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 separate rule for Static Field against players, so nothing more is stated here.

Build notes

• One hard point plus +skills is the usual investment: 9 mana at every level, 25% at every level, and the radius is the only thing a point buys (+0.67 yards each).
• Hard points here are +5% each to Nova; that, not the radius, is the reason to put more than one point in.
• Against a boss in Hell, resistance decides everything: 75% lightning resist cuts the 25% to 6.25% of current life a cast, and -% enemy lightning resistance is the one stat that raises it above 25%.