Bone Wall

Creates an impassable barrier of bone and debris.

Bone Wall is a level 12 Necromancer spell (Poison and Bone tree, requires Bone Armor; it unlocks Bone Prison). It raises a line of bone segments across the targeted point that nothing walks through. The wall has life, not a damage number: the base life of the bonewall unit plus +25% a level past the first, 475% at level 20, plus +10% per hard point in Bone Armor and Bone Prison. It stands for 24 seconds at every level or until a segment is destroyed, and costs a flat 17 mana.

The numbers

• Life is calc1, "HP % Modifier": Param1 25 ("HP % per level") times the level minus one, plus Param8 10 ("HP % synergy") times the hard points in Bone Armor and Bone Prison. 0% at level 1, +475% at level 20, +725% at level 30. The Basin's page writes the same rule as 25 × level − 25.
• Duration is Param2 600 frames at 25 a second: 24 seconds at every level, so it is left out of the table.
• Segments: Param3 8 with Param4 0 a level, and calc2 ln34 is "# of wall missiles created per side ÷ 2". The Basin says the wall's length grows slightly with level.
• Mana is a flat 17.

The life bonus reads the full skill level (lvl), so +skills count; the synergy reads blvl, hard points only.

The base the percentage is applied to is the wall unit's own, which the Basin's page gives by difficulty: level 7 with 19 life and 35 defense in Normal, level 40 with 147 life and 174 defense in Nightmare, level 73 with 431 life and 334 defense in Hell. Its resistances there are 0 physical in Normal and Nightmare and 50 in Hell, 70, 90 and 90 cold, 70, 200 and 200 poison, with 0% drain and chill effectiveness. The Basin also gives it a damage regeneration of 2.

How it works

Bone Wall is a cast construct: no attack roll, no damage. It is placed along the line perpendicular to the line from the caster to the targeted point, centred on that point, so you aim across the gap you want closed. The Basin's rules for the wall:

• It collapses when any one segment is destroyed or when the 24 seconds expire.
• Summon Resist does not apply to it, and friendly auras and buffs do not either; hostile auras do.
• It cannot be cursed, although Battle Cry and Cloak of Shadows still apply.
• It is summoned but it is not a pet: monsters that deal extra damage to pets deal their normal 100% to it.

One broken segment drops the whole wall. In Hell a monster pack that focuses one segment of a low-level wall opens it in moments; the life percentage is what buys the seconds.

Synergies and +skills

Two skills feed Bone Wall, each at +10% life per hard point (Param8 10): Bone Armor and Bone Prison. Both read blvl. In return Bone Wall is the Necromancer's widest synergy giver: each hard point in it adds +15% magic damage to Teeth, Bone Spear and Bone Spirit, +15 damage absorbed to Bone Armor, and +10% life to Bone Prison. A hard point here is worth +25% wall life; a +1 from items is worth the same +25% on the wall and nothing to any of the five skills it feeds.

Against players

A wall deals no damage and casts no state on a player; it only blocks the way until it is broken or expires. See Player versus Player.

Build notes

• At level 20 each segment has +475% life for 24 seconds at 17 mana; at level 1 it is the bare unit. The duration does not grow, so points are life only.
• The twenty hard points a bone caster puts here for Teeth, Bone Spear and Bone Spirit (+300% magic damage) make the wall itself a level 20 wall; its own synergies from Bone Armor and Bone Prison are the cheaper way to make it tougher still.
• Aim across the approach, not at the monster: the wall is laid perpendicular to your line of sight.