Fire Wall

Creates a wall of flame that burns nearby enemies.

Fire Wall is a Sorceress Fire skill (level 18, requires Blaze) and, with Fire Ball, the prerequisite of Meteor. It lays a line of standing fire across the target point and burns whatever stands in it. The two numbers that decide it are the damage per second, 1,284–1,307 at level 20 before synergies, and the 1.4-second casting delay that caps how often you can lay a wall.

The numbers

The damage is stored as bit damage in the EMin/EMax columns, scaled by HitShift 4, and the tooltip multiplies it by 25 × 3 ÷ 256: 25 frames a second, three missiles on the target. The minimum bit value starts at 15 and grows +9 a level to level 8, +14 to 16 and +21 a level from 17 on (EMinLev3, 4 and 5 are all 21, so the growth never steepens again); the maximum starts at 20 and grows by the same 9, 14 and 21. That is 70–93 a second at level 1, 496–520 at level 10, 1,284–1,307 at level 20 and 2,268–2,292 at level 30. The line reads lvl, so +skills count.

The casting delay is the row's localdelay of 35 frames, 1.4 seconds, at every level. The Basin's page notes the delay was global in LoD and is local in D2R.

Two tooltip lines read the missile table rather than the skill row and are not in the repo's bank: the wall's length and how long it burns. The Basin's page gives both: each firewall missile burns for 89 frames, 3.56 seconds, and the length grows with level, 6 2/3 yards at level 1, 12 2/3 at level 5, 20 2/3 at level 10 and 35 1/3 at level 20 when cast diagonally (its formula (7 + 2 × ceiling(9 × level ÷ 8)) × 2 ÷ 3); the tooltip prints floor((5 + 2 × level) × 2 ÷ 3). Param1, the cap on walls alive at once, is 0: the table writes no cap.

Mana is 22 at level 1 and 1 more a level (mana 22, lvlmana 1, manashift 8): 41 at level 20.

How it works

Casting fires two "firewallmaker" missiles from the target point in opposite directions, perpendicular to the line between you and the target; in their wake they leave static "firewall" missiles that apply the bit damage every frame to whatever stands in them for the 89 frames the Basin gives. It is fire damage, reduced by fire resistance, see Dealing Elemental Damage and Resistances and Immunities; no attack rating is involved.

The tooltip's three-missile convention is the catch. The Basin's page says size 3 targets normally take the full displayed damage, size 2 targets only when the wall runs close to parallel with an edge they stand along (otherwise two thirds or one third), and size 1 targets only ever one third. The wall is best cast on stationary targets or along the path they will walk, so they move down its length rather than across it.

Casting continuously, the Basin's page approximates the ceiling as displayed damage × 89 ÷ cast rate in frames once the first wall expires; with a 40-frame cast rate (the 35-frame delay plus the action frame at 63–199% faster cast rate) that is 2.225 × the displayed figure.

A non-immune monster standing in the fire does not regenerate, since any damage in a frame stops damage regeneration.

Synergies and +skills

• Warmth: +4% fire damage per level (Param8 = 4) and Inferno: +1% fire damage per level (Param7 = 1); the calc reads skill('Warmth'.blvl) and skill('Inferno'.blvl), hard points only.
• Fire Wall feeds nothing. The Basin's page notes it was a Blaze synergy in LoD; the current table does not have it.
• Fire Mastery multiplies the per-second damage.

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; each frame's tick of the wall is such a hit. The Basin's page gives no other rule for Fire Wall against players.

Build notes

• The +21-a-level bracket runs from level 17 with no steeper step after it, so +skills past 20 add a flat 98 a second per level to the displayed figure.
• Its synergies are weak (+80% from 20 Warmth points, +20% from 20 Inferno points); Fire Mastery and +skills do more for the wall than any synergy.
• The delay, not the mana, limits the output: at 41 mana a cast and one cast every 1.4 seconds plus the action frame, the wall is a cheap skill for its damage.