Is rushing not a thing anymore?

My buddy stopped playing at lvl 30 for a day and i kept goin and then rushed him to nightmare next day and he was getting no xp from anything.

You gotta exp on things within a certain level of you, and if you're a higher level doing the killing it's unlikely he's going to get as much EXP or so I believe.

now i feel bad because i outlvled him by like 70 levels

Well to put it short:

No, rushing doesn't make much sense anymore. You get only experience in areas that are in a 10 level range. So if you're level 30, you get exp in level 20 areas as well as level 40 areas and anything between.

What you could do now: There's the option to display the area level on the minimap. That way you can figure out where he could potentially level up relatively easily.

If you want to avoid some boring map parts , yes , it makes sense , but you have to recover the skipped xp by farming/leveling in other areas. For example in act 5 Abbadon or Icy cellar you can get a few level ups.

It's not 10 levels difference to get xp. I often get at around c.lvl 63-64 in 75-76 areas and still gain xp without problems. It's more likely 12-15 levels between your character level and the area level. I have not made any exact tests , but for sure the cap is not 10

If you get to an arrea and don't gain xp , you need to go a bit behind to gain more level(s)

thank you for the replies, im just gonna start an alt char to play with him for those levels otherwise he will prob get bored and quit ><