5e Homebrew Rules

This homebrew is for the fifth edition of Dungeons & Dragons.

Combat

Concentration

Saving throws to maintain concentration on a spell use Intelligence instead of Constitution. Any rule referencing "Constitution saving throws to maintain concentration on a spell" or similar language is changed to use Intelligence instead of Constitution.

Death Saving Throws

Each time a character fails a death saving throw they gain a level of exhaustion.

Fumbles

During combat, rolling a natural 1 on an attack roll is a fumble.
For player characters who fumble, roll on the following table to determine the effect:

Non-player characters who fumble are always bemused and lose the rest of their turn.

Potions

Drinking a potion can be done as an action or a bonus action. Administering a potion to an unconscious character requires a full action.

Saving Fallen Allies

To administer healing items to a prone character, you must be prone in the same square or an adjacent square. This applies to potions, healer's kits, and using your Medicine skill. Healing spells do not have this requirement, even spells with a range of touch.

Medicine and Healer's Kits

If you are proficient in Medicine, you may spend your action to make a Wisdom (Medicine) check and try to stabilize a dying character: if your check result is at least 10, the character is stabilized and no longer dying.
If you use either a healer's kit or make a Medicine check to stabilize a dying character, that character may spend hit dice and recover hit points according to the rules for taking a short rest. The maximum number of hit dice the stabilized character may spend depends on the source of healing and your check result.

Healing source	Maximum spent hit dice
Healer's kit (1 dose)	1 hit die
16 Medicine check result	1 hit die
23 Medicine check result	2 hit dice
30 Medicine check result	3 hit dice

In a single action you can both make a Medicine check and use a dose from a healer's kit on the same target.

Outside of Combat

If a character is wounded but not dying, you can spend 10 minutes and use a healer's kit, perform a Medicine check if you are proficient, or do both to a single target. Both you and the target must stay in place during this 10 minutes.

Spells

Counterspell

The text of the counterspell spell is replaced with the following:

You attempt to interrupt a creature in the process of casting a spell. The creature must make a saving throw using their spellcasting ability against your spell save DC. On a failure, the creature's spell is countered and has no effect.
At Higher Levels: When you cast this spell using a spell slot of 4th level or higher, the spell save DC is increased by 1 for each slot level above 3rd.

Misc

Thievery

The thief class has been outlawed since third edition. Nevertheless, various fey and fiends (not to mention your fellow elvenoids) may try to take your coin, by subterfuge or force.

When you notice a coinpurse has been stolen from you, roll 1d20 and multiply the result by your current level. You lose that much wealth in gold coins, which goes into the stolen coinpurse in the form of various gems and coinage. If you lack sufficient wealth, items may be stolen instead of a coinpurse.

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Player characters may not steal or hide treasure from other party members.

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Adventuring Gear

Acid, Alchemist's Fire, Holy Water, and Hunting Traps

Acid, alchemist's fire, holy water, and hunting traps made in Rakvalinor deal double damage.

Torches

Rakvalinor torches used as an improvised weapon deal 1d6 fire damage. Torches that are dropped on the ground while drawing a weapon have a 50% chance of being extinguished and destroyed.

Caltrops and Ball Bearings

Rakvalinor caltrops deal 1d4 damage to a character that fails their Dexterity save.
1 gold coin's worth of caltrops can cover two squares on the battlemap, and 1 gold coin's worth of ball bearings can cover eight squares. It takes an action to scatter either on a single square.

Underwater Combat

While underwater, creatures have resistance to fire damage and vulnerability to thunder damage, because water is incompressible, and vulnerability to lightning damage because water is an electric conductor.

Legendary Resistance

The Legendary Resistance of all monsters is replaced by the following:

Legendary Resistance. (x/day) If this creature would fail a saving throw, it can roll an additional d20 and may optionally use the new roll for its check result.

Monsters may use this Legendary Resistance twice as many times per day as their original power, and they may use Legendary Resistance multiple times on a single saving throw.