Sending out a mass tweet to answer Fallout 4 questions surrounding the level cap and endgame content, Bethesda said:
To our fans who’ve asked: Fallout 4 doesn’t end when the main story is over and there is no level cap. You can keep playing and leveling.
— BethesdaGameStudios (@BethesdaStudios) August 6, 2015
The previous Fallout games, Fallout 3 and New Vegas, had level caps at launch that were raised in post-launch DLC.
With Fallout 4 not including a level cap, do you think you’ll play it for more than 400 hours?