Jester David
Hero
As written, Second Wind lets Fighters bypass the hit dice limitation on self healing and effectively regenerate every hour. I'm using the Slow Healing DMG option so that doesn't work for me. IMC I'm changing it to:
"Second Wind
On your turn, you can use a bonus action to regain hit points equal to 1d10 + your
fighter level. Once you use this feature, you must finish a short or long rest (and have taken damage from combat etc - not self-inflicted) before you can use it again."
I think [MENTION=67338]GMforPowergamers[/MENTION] nails the house rule below. Don't worry about getting the perfect phrasing or limitations for the power, just warn the players if they abuse or exploit loopholes in the rules (such as taking endless short rests to heal 5x faster than normal) there will be consequences.
And don't draw attention to the potential loophole and hope the players won't notice. If they do, glare at them and just say "please don't do that."
And, realistically, this doesn't dramatically impact play, as the rest of the party will still be healing slowly. The fighter can't go off on their own and adventure. The party adventures at the rate the slowest party member to heal.