The following house rules apply to my games:
When rolling with either advantage or disadvantage, rolling either a critical success or critical failure on both dice results in more significant positive or negative outcomes.
When a creature scores a critical hit, it rolls damage normally. However, it then adds the maximum roll possible for each rolled die to the total damage. For example, if a creature would deal 3d6+4 damage with an attack and scores a critical hit, the creature instead deals 3d6+4+18 damage.
Tracking mundane ammunition, as well as supplied such as food and water, is not required. Magical ammunition must be tracked as normal.
When a creature has two hostile creatures on opposite sides of it, that creature is flanked. Melee attacks against flanked creatures have a +2 bonus to hit.
Depending on circumstances, skills may optionally use different Ability Scores than default. For example, an intimidation check may use Strength instead of Charisma if the character making the check physically intimidates the target of the check.
When determining HP gained on level up, you may roll and take the higher between your roll and the flat value described by the PHB.
When you make a ranged attack roll while prone, you do not have disadvantage on the roll unless you are unable to stand up.
Any character can make a DC 15 Medicine Check to heal another character, expending 1 use of a healer's kit in doing so. A failed check restores 1d6 HP, while a successful check restores 1d6+2+half the recipient's number of hit dice. For example, a level 6 character would be healed 1d6+2+3 points as a result of a successful check.
A character may only be healed in this way once per short rest.
A character can spend their downtime in a number of ways, including crafting and training.Please see Downtime Activities for more information.