The new keystone rune of Precision, Press the Attack says the target will get more damage "from all source". But I found that the damage of Vayne's w cannot be boosted by this runes. Is that a bug? Or true damage cannot be boosted?
Tristanl0l2 votesTrue damage is true damage. It can't be amped up or defended against by any means
Shadòw2 votestrue damage cannot by amplified by anything apart from predetermined scalings.
Teridax681 votesThis is the reason. More recently, there have been some exceptions, but as a general rule, true damage is completely unaffected by damage modifiers, so runes shouldn't be able to amplify it either.
Tenth Leper2 votesI cannot confirm or deny, I am afraid, but I believe %damage increases AND %damage reductions are ignored by true damage.
You can still use runes to optimize true damage though. You can get more attack speed for vayne, more hp or cdr or ap for cho and darius, etc.