Otherworldly Patron: Hadar (PEACH)

[Vogie]

Good point, that is a lot of dice that could potentially be applied to the check to break free. However the net when attacking applies the restrained affect as apposed to the grapple affect. But as you pointed out the tendrils attacks as bonus action wile the net is an attack action. This raises a question I’ve been curious about. How do you go from grappled to restrained? I know the feat that allows the grappler to restrain as a bonus action. However I don’t see it applying to this scenario. So how could you restrain with this ability? It’s a huge difference in negative disadvantages. Grappled is movement reduces to 0, restrained attacks have disadvantaged attacking is at advantage and DEX saves are disadvantaged.

By RAW, you can't. The Tavern Brawler feat allows you to grapple as a Bonus action, but that does not apply here.

The tentacles only allow you to grapple or deal damage, and you can only attack with them as a bonus action. However, they have reach, so a range of 10 ft, so it's very similar to having that ability.

If your Hadarlock has 13+ Strength, they can pick up the Grappler feat. That would allow them to grapple as a bonus action via tentacles, then restrain as an action using the following:

You can use your action to try to pin a creature grappled by you. To do so, make another grapple check. If you succeed, you and the creature are both restrained until the grapple ends.

However, it would restrain the 'lock as well, even though he's 2 squares away. However, you may still want it, because of the "You have advantage on attack rolls against a creature you are grappling".

If you were to instead do the Net Throw/Grapple with Both Tentacles combo I mentioned above, the target would be restrained (because they're in the net), and the grapples would be redundant - Until the target breaks out of the net. They'd have to use multiple attacks AND roll absurdly well to beat the Net/Grapple/Grapple absurdity. Since the Net is always thrown with disadvantage, you can remove that by using your Chain familiar to provide advantage, or the Grappler feat to grapple first, then throw the net using the above-mentioned bonus.