What does DMG Mod: -50% mean?

[dakaa`]

As titled.

[FDru]

It means your final damage is reduced by 50% (seems to be rounded up).

[RockType]

To put it another way, It's an attack that hits for half your regular attack damage. Some attacks have positive modifiers (meaning they do MORE than the baseline), but most are either neutral or deal less damage in exchange for AoE and effect damage.

Regardless, all of the damage is calculated from your base weapon damage. Including spells.

[Flowernose]

My weapon 27-30+Enemy proc 15=My damage 12-15
And the message stating my damage will be lowed by 15% is called "Dmg mod"

Im asking a question.Is this true?

[RockType]

Yes

[Tenebrae]

As others have said, it simply means the damage output from that skill is at a 50% penalty against the hero's regular attack, rounded up. If your hero has an upper limit attack of 30 and the move has a DMG Mod: -50% then, yes, the upper limit of that attack will be 15 before protection and crit are applied.