Currently these are the homebrew rules we are trying out and may be subject to change.

Rule 1:  Going to zero HP

When a character goes down to zero health, they are in the process of dying.

1) that character is considered incapacitated 

2) that character gains 1 level of exhaustion and 50% reduction of max hit point each time

2) that character drops what its holding and go prone

3) that character speed goes to 5′ and cannot get up

4) that character automatically fails dexterity and strength saving throws

5) attacks against that character automatically has advantage

6) any attacks that hit the character is critical as long as the attacker is within 5′ of the character

Rule 2:  Exhaustion

Exhaustion is different than in 5E.  Each level of exhaustion causes -1 to any check, save, attack, spell save dc.  If you get 11 levels of exhaustion, then you die.  Long rest removes one level of exhaustion, comfortable long rest such as in an inn removes 2 level of exhaustion.   

Rule 3:  Healing potions

You can drink or feed someone a healing potion as a bonus action but you will have to roll for the results.  If you take a full action to drink or feed someone a healing potion then that potion gives the max healing possible.  

Rule 4:  Help action

Help allowed only for proficient skills and is automatic.  If you tried to help for a task that you are not proficient then you have to roleplay how you do the help with a skill that you do have.  

Rule 5:  DC checks

Degree of success and failure.  Different outcomes with how close or how far you are to the target DC of a task.  

Rule 6:  Grappling

Grappling is considered an unarmed strike with target making a save vs DC of 8 + Strength Bonus + Proficiency bonus.  Grappling can be an opportunity attack

Rule 7:  Criticals

Critical hits automatically max the damage on the extra dice, rolling a second 20 on a D20 after a natural 20 is consider a death blow.  Death blows cannot be changed by luck, potent, silvery barb, etc.  Even if player declares the will use luck, potent, silvery barb on the first 20, the DM will roll a second 20 to see if a death blow occurs.  If a deathblow does occur then we will consider fate being stronger than the power that was used and wasted.

Rule 8:  Things that changes rolls

Lucky can be picked but for each use of lucky, the DM also gets one lucky to use later on.  

Halfling luck is fine to play but on a repeat roll of another 1 then that is the result with very bad luck outcome.

Silvery barb is fine to play as well but then if the reroll still is not a success or turns to a miss hit then the DM choices which of the 2 rolls apply.