Talk:Kog'Maw/Strategy/@comment-99.227.204.241-20111113161013/@comment-4729118-20120117100555

"Ways that grant a "damage reduction" will not diminish true damage. True damage will not bypass absorption shields that block all kinds of damage, but it will damage the shield. Magic-only shields such as Morgana's  Black Shield and the passive on  Hexdrinker will have no impact on true damage."

http://leagueoflegends.wikia.com/wiki/True_damage

you're in the wiki - use it >_>