I am relatively new to actual pnp dnd play, as i lived in a small town with no such comunity.
I'm studying Electroenergetics in a bigger citty and am starting to peek into the dnd world with a bunch of friends.
My pervious dnd experience was from BG,NWN and other similar pc games.
Hit Points, working as intended. This minor change in mechanics,but a HUGE shift of perspective back to the original description of Hit Points in the rule books helps you believe in what them hit points represent. This makes surviving devastating looking situations more plausible. You don't get directly brutalised, you avoid it, but it taps your resources. Only criticals, failed saves and final blows get into your squishy bits. This doesn't change anything, you just have to track wounds and strain on the hp. Acording to the playtests it didn't increase bookkeeping much, cut down on the healing needed (when there were no O SHIT! situations), had the same lethality as without it and increased the immersion becouse situations of parrying and avoiding the direct hit had to be described. The strain can be reset after taking some time go get your bearings togather (5 minutes of rest), but the wouds have to be healed the good ol fashioned way. This cuts down on the suspension of dibelief and reduces strain on healing resources. You are battered and bruised, but not rended to a blody pulp if you survive and there was no critical, or failed save. Start of the whole awesome ordeal.