Heavily obscured and opportunity attacks

[Crucius]

Hello peeps

I was in the thick of trying to understand the Darkness spell and Shadow of Moil (not in conjunction, just as is) and I noticed that some people say that heavy obscurement prevents opportunity attacks due to the following clause:


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

PHB 195: Opportunity Attacks. Emphasis mine.

Did you know this? Is this true?

So Shadow of Moil gives you advantage on attack rolls, enemies have disadvantage on attack rolls against you, AND you can walk around freely without triggering opportunity attacks?
Invisibility also stops opportunity attacks, instead of just disadvantage on the attack roll?
Darkness/Fog Cloud can let entire groups walk through hordes of enemies without triggering opportunity attacks?

[Zuras]

Hello peeps

I was in the thick of trying to understand the Darkness spell and Shadow of Moil (not in conjunction, just as is) and I noticed that some people say that heavy obscurement prevents opportunity attacks due to the following clause:



PHB 195: Opportunity Attacks. Emphasis mine.

Did you know this? Is this true?

So Shadow of Moil gives you advantage on attack rolls, enemies have disadvantage on attack rolls against you, AND you can walk around freely without triggering opportunity attacks?
Invisibility also stops opportunity attacks, instead of just disadvantage on the attack roll?
Darkness/Fog Cloud can let entire groups walk through hordes of enemies without triggering opportunity attacks?

Yes. Using Darkness or Fog Cloud to allow disengaging is a common tactic.

[RSP]

It’s true that you need to see someone to get an Opportunity Attack on them. Those things that heavily obscure prevent OAs. They also prevent targeting from anything that requires seeing the target, like some spells.

[Crucius]

Awesome! Thanks!

Always nice to get an N-th opinion!