Thunder Storm

Summons a deadly thunderstorm that strikes your enemies with bolts of lightning.

Thunder Storm is a Sorceress Lightning skill (level 24, requires Nova and Chain Lightning). It is a buff on the Sorceress: for its duration a storm follows her and, at a fixed interval, drops a bolt on one enemy within its radius. Two numbers decide it: the damage of each strike, 195–294 at level 20 before synergies and mastery, and the interval between strikes, which the Basin's table puts at 1.64 seconds at level 20.

The numbers

The damage is the one Sorceress lightning range with a real minimum. Both ends come from the table's EMin 1 and EMax 100 with HitShift 8, and both grow by the same brackets: +10 a level to level 8, +10 to 16, +11 a level past that. That is 91–190 at level 10, 195–294 at level 20, 305–404 at level 30, a spread of 99 at every level. The line reads lvl, so +skills count.

Duration is ln12: Param1 3,600 frames (the table's "Buff Duration baseline") plus Param2 600 a level ("Buff Duration per level"), at 25 frames a second: 144 seconds at level 1, 24 more a level, 600 seconds at level 20.

Two lines never change and are left out of the table: the mana, 19 at every level (mana 19, lvlmana 0, manashift 8), and the radius, Param7 17 shown as × 2 ÷ 3, which is 11.33 yards around the Sorceress.

The strike interval is the row's perdelay, (100 − dm56) × par4 ÷ 100 + par3: Param3 25 is the "Periodic Damage Rate Min" and Param4 100 the "Periodic Damage Rate Multiplier", and the diminishing term it subtracts is not something the repo's bank can compute, so it is not in the table above. The Basin's page prints the interval it computed for its era: 4.4 seconds between strikes at level 1, 3 seconds at level 5, 2.28 at level 10, 1.64 at level 20, 1.36 at level 30, 1.2 at level 40.

How it works

Thunder Storm puts the state "thunderstorm" on the Sorceress (auralencalc ln12) and is periodic (periodic 1): every interval it fires the "thunderstorm1" missile at a target. The Basin's page says it cycles between the targets within the radius, striking each in turn before returning to the first, so a lone target in range takes every strike. The interval also runs between the cast and the first strike. Each strike is lightning damage, reduced by the target's lightning resistance, see Dealing Elemental Damage and Resistances and Immunities; there is no attack roll.

The Basin's rules on levels: the skill level is applied when cast and sets the base damage, interval and duration; a higher-level cast overwrites a lower one but not the other way round, and an equal level resets the duration. Lightning Mastery and other +% Lightning Skill Damage are applied to each strike as it happens, so they are read from your gear at the moment of the strike, not of the cast.

With no hard point, the Basin says the storm stays up only while the item that grants it is equipped: remove it and the storm goes out, and it stays out until cast again.

Synergies and +skills

• Static Field: +7% lightning damage per level (skills.txt Param8 = 7; the calc reads blvl, hard points only). It is the skill's only synergy.
• Thunder Storm feeds no other skill.
• +skills raise the damage and the duration (lvl); the synergy percentage does not move with +skills.

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 Thunder Storm against players.

Build notes

• The cost is one cast of 19 mana for 600 seconds at level 20; nothing else on the skill spends mana.
• Hard points in Static Field are +7% a strike here and are the only way to raise the damage past +skills; the Static Field points cost nothing on that skill's own numbers, which never change.
• The interval shortens most at low levels (4.4 seconds at level 1, 2.28 at level 10) and little past 20, so +skills past 20 mostly buy damage, not strikes.