So I’m playing a Blood Hunter. She’s at 3rd level and I haven’t been rolling very well for her HP. Which you don’t want with a Blood Hunter. Next level is the Ability Score Increase/Feat deal and I’m torn. I’d like to get her Dexterity up to 18 (it’s at 16 right now), since that’s her attacking score, but I’d also like to give her the Tough feat so I don’t have to worry so much about HP.

What do you think?

Depends on how much you want to use the blood rites and blood maledict features. They are core features, especially the rites, and if have sub-par HP due to low rolls then you are better off with the Tough feat or increasing your Constitution. You need the HP to use the class, it's the cost for the powerful abilities. I'd say that's more important than an extra +1 to attack (and possibly AC).

If you're dual-wielding the extra opportunity for attacks, especially with Extra Attacks at your next level, make up for a less-than-optimal attack bonus. Although +3 ability mod for attacks is not that bad for 1st tier play. It's actually not a race to get the ability mods up to highest. The +3 ability mod to attacks will actually get you by even in top-tier (up to level 20) play, it's not ideal at all, but still works. The ability mods are not super important (but yes, are important) thanks to multiple attacks and a scaling proficiency bonus.

I would recommend Tough now, and then increase dex at level 8. Level 12 may be a feat or +2 con and level 16 could be your dex again.

Thanks! Yeah, I’m pretty sure I’m wracking my brain over nothing. I gave her Dueling, but I also went with Order of the Lycan subclass for her, so she’s still got that good bonus attack. On top of that, her other two key abilities are also really solid. Constitution and Wisdom are both also at 16.

I dunno, maybe I just like the big numbers.

This is the exact reason we went with the “Average or Better” rule for rolling HP. You roll hp and get the average die roll (rounded up) or the result of your roll, whichever is higher. It limits the likelihood that one of them will get greased by a crit due to poor luck on their hp rolls, allowing me more freedom with the encounters I throw at them.

Hybrid transformation is going to help your HP with resistance to most common damage types when you transform, and also with the extra +1 bonus to AC. The nice thing about pumping DEX is that it helps you on the offense side as well as the defense side (assuming you are wearing armor that allows a +4 DEX bonus). I also think that of the available options, dueling is probably the way to go even though you may not end up benefiting all that often from it if you use your claws. The Lycan Blood Hunter who plays in my group stacked his stats in such a way that he could add 1 to his WIS and DEX at level 4 and bring them both up to the next modifier bonus, but he's a STR fighter anyway.

In summary, I think both choices would help you out, but if you don't mind running light armor, I recommend the DEX boost at level 4. How is your WIS? Bloodlust is always a concern for Lycans.

Thanks for your thoughts. Her Wisdom is at 16, same as her Dexterity right now.