Quote Originally Posted by Felis View Post
To increase the levelcap in Heavensward you only need the expansion and don't need to clear the 2.x story.
I'll be surprised if you actually need the expansion in order to level past 50. They never did this in FFXI - in fact, they went out of their way to provide methods for folks who choose not to buy the expansion to continue leveling (added higher level mobs to old zones).

In fact, I think it's highly likely that experience points are going to be added to level 50 Main Scenario quests and sidequests, so that folks newer to the game can continue leveling as they proceed through Main Scenario.

Heavensward will offer higher level open world mobs (but who levels on those?), higher level FATEs, and higher level dungeons, but for folks who choose not to pick up the expansion there will still be Dungeon Roulette, and possibly other methods added as well. It will be more difficult to level up without the expansion, but I doubt it will be impossible to level up without the expansion.