Thorns

When active, aura reflects melee damage taken by you and your party back at your enemies.

Thorns is a level 6 Paladin Offensive Aura with no prerequisite; it opens Sanctuary. While it is active, a melee attacker that hits you or an ally in the radius takes damage back: a percentage of the physical damage it dealt and, in the current game, a flat amount as well. Two numbers decide it: the percentage, 250% at level 1 and 1,010% at level 20, and the flat return, 4 at level 1 and 144 at level 20.

The numbers

The percentage is Param3 250 as the baseline and Param4 +40 a level: 1,010% at level 20, 1,410% at level 30. The flat return is the EMin column and its five brackets: 4 at level 1, +4 a level to level 8, +8 to 16, +12 to 22, +16 to 28 and +20 past that, so 144 at level 20. The radius is Param1 16 plus Param2 2 a level, times two thirds for yards: 10 2/3 yards at level 1, 36 at level 20. An aura costs no mana. Every line reads lvl, so +skills from gear and an Aura When Equipped item count. The Basin's older page prints only the percentage; the flat line is the current table's.

How it works

Thorns is an aura with the row's thorns state on the caster and on every ally in range, refreshed every 2 seconds (perdelay 50). It carries two stats: item_attackertakesdamage, the same stat as the item modifier Attacker Takes Damage, set to the flat value, and thorns_percent, the percentage. There is no hit check and no cast. The Basin's page gives the rules of the return:

• The percentage is only returned when a melee attack hits and applies physical damage. Missiles and spells return nothing.
• It is based on the final physical damage taken, after your reductions: cutting your physical damage taken cuts the return, and negating it returns nothing. See Taking Damage.
• The return is always applied to the attacker, but it is physical damage the attacker can reduce or negate: a physical immune takes nothing.
• Returned damage is cut to 1/8 when it is applied to a player or a mercenary.

Thorns pays out of what you actually take: the better your damage reduction, the less comes back. Against a physical immune nothing comes back at all.

The Basin's page lists the other supplier: the Act 2 Combat mercenary hired in Nightmare or, in the current game, Hell carries Thorns.

Synergies and +skills

No synergies: Thorns has no dsc3 lines and no …SymPerCalc column, and it feeds no other skill. All three lines read lvl, so a +skill from gear raises the aura exactly as a hard point does. The Basin's Conversion page notes that a monster cursed with Amplify Damage before it is converted keeps the curse, which raises what Thorns returns through the convert.

Against players

Thorns never attacks a player itself; it returns damage to one who hits you in melee. The Basin's page says the returned damage is cut to an eighth when it is applied to a player or a mercenary, and a player's hit on another player is cut to 17% of its value (difficultylevels.txt PlayerDamagePercentVSPlayer) before anything else, see Player versus Player, so the physical damage the return is based on is small to begin with.

Build notes

• Level 20 reads 1,010% plus 144 returned in a 36-yard radius, for no mana; +skills raise all of it.
• The return scales with the damage you take, so it rewards being hit for real: damage reduction and a high block rate work against it.
• The flat return is new to the current table and does not depend on the hit's size; at low levels it is most of what a weak hit returns.