According to Associate Game Director Joseph Piepiora, getting to Level 100 in Diablo 4 will take over 150 hours for the average player. Piepiora reached out on Twitter to clear up confusion based on different statements regarding level 100 playtime.
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Just two weeks ago, members of Team 3 stated in a PC Gamer interview that hours played to reach max level in Diablo 4 should be around 80 or more.