From HoNwiki
In Heroes of Newerth there are multiple ways to modify what your attack does.
These are called Attack Modifiers and Exclusive Modifiers.
Attack Modifiers
Attack Modifiers do not stack with each other or themselves at all. They will stack with Exclusive Modifiers.
List of Attack Modifiers
Life Steal
Exception with Abyssal Skull which does stack with other attack modifiers because it is applied through an aura.
Other Attack Modifiers from Items
- Shieldbreaker
- Frostburn
- Icebrand
- Frostwolf's Skull
- Harkon's Blade (This is counted as an Attack Modifier only when activated, when not active other attack modifiers will work).
Attack Modifiers from Hero abilities
- Beardulon's Tangled Claw, Wildsoul's Summon
- Vindicator's Master's Incantation (Only counts when activated)
- Arachna's Webbed Shot (Only counts when activated)
Exclusive Modifiers
Exclusive Modifiers are slightly rarer than Attack Modifiers.
They will not stack with them self, you can not have multiple forms of Mana burn, however they do stack with other modifiers, you can have Multiple Exclusive Modifiers and an Attack Modifier stack together on a single hero.
If you have more than one source of the same Exclusive Modifier, the game will use the stronger one.
List of Exclusive Modifiers
Mana Burn
- Nullfire Blade
- Magebane's Mana Combustion
Bash - These have multiple chances to bash, but will share a cool down.
- Brutalizer
- Pestilence's Gore
Lightning