Homerules

Flanking (Custom Variant)

(same as normal Flanking rule except it grants a +2 bonus to attack instead of advantage)
When making a melee attack, you gain a +2 bonus to the attack roll if your opponent is threatened by a character or creature friendly to you on the opponent’s opposite border or opposite corner. When in doubt about whether two friendly characters flank an opponent in the middle, trace an imaginary line between the two friendly characters’ centers. If the line passes through opposite borders of the opponent’s space (including corners of those borders), then the opponent is flanked. Only a creature or character that threatens the defender can help an attacker get a flanking bonus. Creatures with a reach of 0 feet can’t flank an opponent.
Exception: If a flanker takes up more than 1 square, it gets the flanking bonus if any square it occupies counts for flanking.

Attunement Scaling

You maximum attuned items is equal to your proficiency bonus.

Potion Sickness

The maximum amount of potions you can consume within the span of an hour is equal to your proficiency bonus. Some potions may contribute more than 1 use towards potion sickness. Very Rare potions count as 2 consumptions, and Legendary potions count as 4 consumptions. Any potion consumption beyond the limit results in a Constitution saving throw to avoid vomiting the potion, gaining no benefit from it. The save DC depends upon the potion rarity, starting at DC10 for Common, DC12 for Uncommon, DC14 for Rare, DC16 for Very Rare, and DC20 for Legendary. Upon failing this save, you will immediately vomit the potion.

Combat Fatigue

When a creature is reduced to 0 hit points and isn't instantly killed, it immediately gains 1 level of exhaustion.

Last Stand

When a player is dying, they may wish to push themselves to their utter limits to help their teammates. Instead of rolling a death save, they may choose to declare their Last Stand. Upon doing so, they regain 1 hit point, and gain temporary hit points equal to half of their maximum hit points (rounding down). They may then take their full turn as normal, during which they gain advantage on all d20 rolls. When they end their turn, they die.

Damage at 0 Hit Points

When you take any damage while you have 0 hit points, you must roll a death saving throw. A roll of 10 or higher does not count as a success, while a roll of 9 or lower counts as a failure. If the instance of damage you suffer is greater than 1/4 of your maximum hit points (rounded down), you automatically fail the death saving throw. If the instance of damage you suffer is greater than 1/2 your maximum hit points (rounded down), you automatically suffer 2 death saving throws. If the instance of damage you suffer is greater than your maximum hit points, you die instantly.

Knocking a Creature Out

When a creature is reduced to 0 hit points, you may wish to render it unconscious but stable. To do so, the attack and damage dealt must meet specific conditions. Certain weapons are more capable of dealing non-lethal damage, such as unarmed attacks, a quarterstaff, or a club. Certain types of damage are also more conducive to non-lethal damage, such as Force or Bludgeoning damage. You may also opt to 'pull your punches', accepting disadvantage on an attack roll to represent reducing the amount of power you are putting into the attack. Lethal weapons may be creatively wielded in a manner to deal non-lethal damage, such as using the flat of a blade to bludgeon someone unconscious, but doing so is an unnatural and unintended use of the weapon, causing disadvantage on the attack roll unless you are proficient in using improvised weapons. In the end, what determines lethal or non-lethal sources of damage are DM discretion, and can be influenced by a players creative or restrained use of spells, attacks, and abilities.

Modified Exhaustion

Each level of Exhaustion incurs a penalty to your d20 tests equal to the level of Exhaustion you have. For every 2 levels of Exhaustion you have, your Speed is reduced by 5 ft. Whenever you finish a Long Rest, you remove 2 levels of Exhaustion.

Dazed Condition

You may encounter creatures that inflict the Dazed condition. The Dazed condition has the following effects:
Dazed. You cannot take reactions. You cannot concentrate on spells, and any concentration is broken. On your turn, you may use either an action, bonus action, or movement.

Help Action (Custom Variant)

The Help action is changed in the following way: When used to aid a character making a skill check, if the aiding character does not have proficiency in the skill, they lend a +2 bonus to the roll. If the aiding character has proficiency in the skill, the skill check is made with advantage. For attack rolls it still always grants advantage.

Act-First Initiative

If combat emerges out of a roleplaying situation, the person that verbally roleplayed attacking first will always be top of the initiative order, and everyone else rolls. In situations where no one clearly acted first, initiative is rolled as normal.

More Leveled Spells

You may only cast 1 leveled spell per native action type, per turn. Native actions are the action the spell would cost before being modified by a feat, feature, or ability (such as metamagic quickened spell, Cartomancer feat's Hidden Ace feature, ect.). This means you may use one action leveled spell, bonus action leveled spell, and reaction leveled spell each turn. Items bypass this restriction if the item allows the spell to be cast using a different action than it normally would, in which case the action described by the item is that spells native action.