Energy Shield

Creates a magical shield that consumes mana instead of health when you take damage.

Energy Shield is a Sorceress buff (Lightning tree, level 24). While it is up, a share of every hit you take is paid from your mana instead of your life, at a price in mana per point of damage. Two numbers decide everything: the share the shield takes, which grows with the skill's level, and the price, which only Telekinesis lowers.

How much it absorbs

The share comes straight from the skill's damage columns in skills.txt: a base of 20% at level 1, then +5 a level up to level 8, +2 a level to 16, +1 a level from there, and never more than 95% (the tooltip's calc is min(edmn, 95)). Levels past 20 come from +skills on your gear, so they count: a level 30 shield absorbs 85%, and the 95% cap is reached at level 40.

Duration is 144 seconds at level 1 and 24 seconds more a level (Param1 3,600 frames + Param2 600 frames a level, at 25 frames a second). Recast before it runs out; the shield also drops the moment your mana reaches zero.

What it costs

mana spent = damage absorbed × (32 − Telekinesis hard points) ÷ 16

Energy Shield itself has no level of mana efficiency: at 0 points in Telekinesis every absorbed point of damage costs 2 mana (Param5 = 32 sixteenths; the tooltip prints it as "200% mana consumed per damage"). Each hard point in Telekinesis takes one sixteenth off (the calc reads blvl, the base level, so +skills from items do not help here):

With no Telekinesis a 1,000-damage hit at 75% absorb drains 1,500 mana. The synergy is not optional on a build that leans on the shield.

Where it sits in the order

The Amazon Basin's defender order, which the game applies to every hit you take, is: the unit modifier (the player-versus-player rule) → Bone Armor or Cyclone Armor → Energy Shield → Damage Reduced or Magic Damage Reduced → your resistance → percentage absorb → flat absorb. So the shield takes its share of the full hit, before your resistances and before physical damage reduction, and only what it leaves goes through them. That is why an Energy Shield Sorceress can run with low resistances and a big mana pool: the resistances only ever see a quarter of each hit. See Taking Damage for the whole chain.

What it never absorbs

The Basin lists what the shield covers: physical, magic, fire, lightning and cold damage, stamina damage and mana damage. It does not absorb poison damage, and it does nothing against Open Wounds, Crushing Blow, or Sacrifice's self-damage. Poison and Open Wounds tick straight through to life, so poison resistance and a source of replenish life still matter on a shield build.

When mana runs out

When the mana the shield would spend is more than you have, your remaining mana absorbs as much as it can pay for and the rest of the hit lands on your life. At zero mana the shield expires. Mana leech, Regenerate Mana, Damage Taken Goes To Mana and a large pool from Energy and Mana are what keep it up; a Mana Burn monster is the shield's natural enemy.

Against players

The player-versus-player rule applies first: a player's hit on another player is reduced to 17% of its value (difficultylevels.txt PlayerDamagePercentVSPlayer) before the shield takes its share, so the mana a duel costs is a sixth of the same hit in the field. Everything else works as above; the shield's share and its mana price do not change in player-versus-player. See Player versus Player.

Build notes

• Hard points in Telekinesis are worth more than hard points in Energy Shield past level 20: the price drops by 1/16 a point while the share only grows by 1 a level, and +skills raise the share but not the synergy.
• The mana pool is the shield's life pool: with 2,000 mana and Telekinesis at 20 the shield can pay for about 2,650 points of damage before it fails.
• Faster Cast Rate does not change the shield. Casting it in town is allowed.