Does The Idea Of Threatened Squares Exist in 5e?

Question

Maybe I'm reading this wrong, or perhaps I just never played right in 3.5, but I seem to remember this idea of "threatened squares" which appears done away with in 5e.

A mighty warrior approaches a giant wielding a club. The giant has a reach of 10 feet. The warrior gets within 10 feet of the giant (newly within range) then moves one more square, now 5 feet away, in order to make it's own attack.

In 3.5 the warrior moved through a threatened square, provoking an attack of opportunity.

In 5e the warrior did not move out of reach (only into reach), thus did not provoke an opportunity attack.

Do I have a proper understanding of how this same scenario is effectively different given the new versions of the game?

Answer 1

You're correct.

In 5e, opportunity attacks occur only when you move out of reach (PHB 195):

You can make an opportunity attack when a hostile creature that you can see moves out of your reach.

Thus, moving within someone's reach does not provoke an opportunity attack.

The Polearm Master feat more closely (but not exactly) resembles your 3.5 scenario, though (PHB 168, emphasis added):

While you are wielding a glaive, halberd, pike, or quarterstaff, other creatures provoke an opportunity attack from you when they enter your reach.

Not having played much 3.5e, I can't remember exactly how attacks of opportunity worked in that edition.