Venom

Add poison damage to your weapons.

Venom is the last skill of the Shadow Disciplines tree (level 30, requires Fade). Cast on the Assassin, it puts a poison on her weapons: every hit that lands delivers a large dose of poison damage over a very short fixed length of 0.4 seconds. The two numbers that decide it are the damage per hit, 425–445 at level 20, and that length, which is why Venom reads as thousands of poison damage a second on the character screen.

The numbers

• Mana is a flat 12 at every level and the buff can be cast in town (InTown 1).
• Duration is ln12: Param1 (3,000 frames) plus Param2 (300) a level, at 25 frames a second: 120 seconds at level 1, +12 a level, 348 seconds at level 20, 468 at level 30. The Basin's page prints both the 1.10-era formula (116 + 4 a level) and the D2R one (108 + 12 a level); the table matches the D2R one.
• Poison length is ELen, 10 frames = 0.4 seconds, with no per-level column, so it is the same at every level and is left out of the table.
• Poison damage is EMin/EMax (24 and 32) with a HitShift of 6, applied over those 10 frames: the tooltip's calc is the bit rate times the length over 256, which gives 60–80 at level 1. The brackets EMinLev1–5 and EMaxLev1–5 (6, 8, 10, 12, 14) add, in damage terms, +15 a level to level 8, +20 to 16, +25 to 22, +30 to 28 and +35 past that, on both ends: 425–445 at level 20, 725–745 at level 30. Per second that is the damage ÷ 0.4: 1,062.5–1,112.5 at level 20, which is what the Basin's D2R table prints.

Every line reads lvl, so +skills from items count; the Basin says +1–3 Venom can spawn on exceptional and elite claws of item level 36 and up.

How it works

Venom is a personal buff (aurastate "venomclaws"): for its duration the Assassin carries poisonmindam, poisonmaxdam and a skill_poison_override_length stat equal to the skill's length (aurastat1–3). The override is the rule that bites, and the Basin's page spells it out: once Venom is cast, the sum of Venom's poison and the poison on your items is applied for Venom's length only; the items' own poison lengths are ignored. A 0.4-second length means the whole dose lands almost at once, which is what makes a short poison strong, but it also means an item's long, slow poison is compressed into the same 0.4 seconds. See Poison Damage for how poison is delivered in bits per frame and why length matters.

The Basin's page adds: a lower-level Venom does not overwrite a higher one, while an equal or higher level does; +% Poison Skill Damage is applied when the buff is cast and again when the poison is delivered by a melee hit; and Venom's rate and length are added to those of Poison Dagger and the javelins of Poison Javelin and Plague Javelin. The weapon normally turns green while it is active, except that Enchant's red takes precedence over the colour (Venom still applies), and on a mercenary the only sign is that the mercenary poisons.

Venom overrides the poison length of everything on your gear: a weapon's poison "over 10 seconds" lands in 0.4 seconds while Venom is up, and nothing on your gear extends Venom's 0.4 seconds.

The poison is delivered by the weapon's hit, so it rides on whatever attack lands, and it is subject to the target's poison resistance and the rules of Dealing Elemental Damage.

Synergies and +skills

No synergies: skilldesc.txt has no dsc3 line for Venom, no synergy calc is on the row, and Venom feeds no other skill. All of its lines read lvl, so a +skill is worth a hard point: a +10 from gear turns level 20's 425–445 into level 30's 725–745 and adds two minutes to the duration.

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; Venom's poison is part of that hit. The Basin's page says nothing else specific about players.

Build notes

• Level 20 is 425–445 poison per hit over 0.4 seconds for 348 seconds on 12 mana; the damage grows faster at every bracket (+15, +20, +25, +30, +35 a level), so late levels are worth more than early ones.
• The length never changes, so Venom's damage is the same whether you hit once or ten times a second; what changes is how many doses land.
• Poison already on your gear is folded into Venom's 0.4 seconds, so Venom raises a poison weapon's burst and shortens its tick.
• Recast with an equal or higher level only, since a lower-level cast will not take over a higher one.