The Chronicles of Kedas
Quaffing a Potion
A player may take a potion on their turn as a bonus action.
Administering a potion to an unconscious ally takes a standard action.
A Natural 1 not only results in an automatic failure, but in a “Critical Failure.” Something bad will result, perhaps your attack will hit an ally, a crossbow string might snap, or you may drop your sword.
Skills and Critical Successes
A Natural 20 while performing a skill check is weighed more heavily than the sum of its total, and while it will generally be an automatic success (within reason) it will also be taken into account narratively, providing an extra flourish to the action or placing you somewhat more advantageously.
Similarly a Natural 1 could spell additional consequences beyond simply failing the result.
Between levels 1 and 4, Resurrection is a sure thing that requires access to the required spell or someone to cast it. Following level 4, a system similar (and perhaps identical) to the Critical Role resurrection system will be adopted.