You are talking Chaos Damage from standing in Caustic Ground
Caustic ground
Caustic Ground is a detrimental ground effect that deals chaosdamage over time. The amount of damage per second inflicted by caustic ground depends on its source.
Sources
Caustic ArrowCaustic ArrowAttack, Projectile, AoE, Duration, Chaos, Bow Level: (1-20) Cost: (6-10) Mana Attack Damage: (55-64)% of base Effectiveness of Added Damage: (55-64)% Projectile Speed: 3260 AoE Radius: 20Fires an arrow which deals chaos damage in an area on impact, and spreads caustic ground. Enemies standing on the caustic ground take chaos damage over time.Deals (8.8-1927.1) Base Chaos Damage per second Base duration is 2.00 seconds Modifiers to Projectile Damage apply to this Skill's Damage Over Time effect +(0-0.6) metres to radius 60% of Physical Damage Converted to Chaos Damage
Additional Effects From 1-20% Quality: +(0.01-0.2) metres to radiusPlace into an item socket of the right colour to gain this skill. Right click to remove from a socket.
Strongboxes with the ContaminatedContaminated Prefix Spreads Caustic Ground Chest plays warning sound (Hidden) prefix
Adjusted a number of Metamorph skills, including the Reliquarian's Firestorm, the Shavronne & Brutus Hover Slam, Tentacle Miscreation projectile skills, the tracking Mortar skills (including those used by Oriath zombies and Kitava's Heralds), Burning and Caustic Ground-creating skills and several others. In general, these will now either deal less damage or be easier to avoid.
The SiegebreakerSiegebreaker Heavy BeltRequires Level 44+(25-35) to Strength(6-10)% increased maximum Energy Shield (6-10)% increased maximum Life +(17-23)% to Chaos Resistance Minions have 5% chance to Taunt on Hit with Attacks Your Minions spread Caustic Ground on Death, dealing 20% of their maximum Life as Chaos Damage per secondPoison the land and they'll have nothing to defend. unique belt now correctly causes your Raised SpectresRaise SpectreSpell, Minion Level: (1-20) Cost: (15-28) Mana Cast Time: 0.85 secRequires Level 28Raises a spectral version of a defeated foe as a minion to fight for you in battle.Maximum (1-2) Raised Spectres Minions have +30% to all Elemental Resistances 55% more Minion Movement Speed Minion Movement Speed is Capped Minions have (105-776) additional Accuracy Rating Raised Spectres are Level (28-70)
Additional Effects From 1-20% Quality: Minions have +(1-20)% to all Elemental ResistancesPlace into an item socket of the right colour to gain this skill. Right click to remove from a socket. to spread Caustic Ground on Death.
We've made performance improvements to ground effects. They now use considerably less bandwidth and server resources. Disconnections or lockstep stuttering near ground effects should occur far less often.
Poison ArrowCaustic ArrowAttack, Projectile, AoE, Duration, Chaos, Bow Level: (1-20) Cost: (6-10) Mana Attack Damage: (55-64)% of base Effectiveness of Added Damage: (55-64)% Projectile Speed: 3260 AoE Radius: 20Fires an arrow which deals chaos damage in an area on impact, and spreads caustic ground. Enemies standing on the caustic ground take chaos damage over time.Deals (8.8-1927.1) Base Chaos Damage per second Base duration is 2.00 seconds Modifiers to Projectile Damage apply to this Skill's Damage Over Time effect +(0-0.6) metres to radius 60% of Physical Damage Converted to Chaos Damage
Additional Effects From 1-20% Quality: +(0.01-0.2) metres to radiusPlace into an item socket of the right colour to gain this skill. Right click to remove from a socket. and Ground Fire should now cause fewer graphical performance issues.
Caustic ArrowCaustic ArrowAttack, Projectile, AoE, Duration, Chaos, Bow
