at full peaceful you can kill them at 80 - This is however unrealistic if you have no combat experience (Excluding foxes and Ants) - You will also need some good armor, fight boars with a helm instead of a bear cape.
The main thing is DON'T let them gain advantage.
I use dash and death or glory to gain IP, remembering to use Oaken Stance and slide when your Defence is 3 quaters depleted. Continue until you have 6 or more IP if you want to gian Advantage and use punch/flex/Bloodlust - then Knock his teeth out, once you think it will be a killing blow. if you're quick enough the boar won't gain advantage.
If you can't beat them that way, it's usually because they're gaining too much advantage, try gaining more IP and using Invocation of Skuld/sidestep to gain advantage. - this takes longer but is much safer.
I hope this helps somewhat
