Avlarin’s Universal Axiom

Villians and Monsters

These changes and additions are used by the DM

Legendary Actions

The following change is made to how legendary actions work:
One legendary action can be used at a time at the end of another creature's turn. Any remaining legendary actions may be spent at the end of the round, and the legendary creature regains all spent legendary actions at the start of the round.
If there are two creatures attempting to use legendary actions, the one with the higher Dexterity score acts first.

Running Mobs

When fighting with large amounts of hostile creatures, it's often best to separate them into mobs. Group them into convenient multiples (4, 5, 10, etc) and use one token for them. It is not recommended that each mob is more than 10 creatures.

Hit Points & AOE's

Round the individual's hit points to the nearest 5 or 10, then multiply the individual's max HP by the number of creatures in a mob. For example, a skeleton's max HP is 13, so round that to 15. A group of 5 skeletons has 50 HP. For every 15 damage they take, one skeleton dies. An AOE spell that hits half or more is considered to hit all of them. A mob consisting of 5 skeletons can be killed with a single fireball. Roll once for every five creatures in a mob.

Attacking & Damage

For attacking, determine the minimum d20 roll for a normal hit plus the individual creature's modifier. Flanking, achievable by surrounding a creature fully, grants advantage. Advantage/disadvantage grants +5, then a +2 for every source of it going forward.

d20 Roll Needed	Attacks Needed for One to Hit
1-5	1
6-12	2
13-14	3
15-16	4
17-18	5
19	10
20	20

Swipe Attacks

A monstrous/bestial creature that attacks with a tail, claw, or similar method of attack may swipe. The area affected is a flat cone equal to the attack's normal reach. Creatures in that area must make a Strength (Bracing) or Dexterity (Dodging) saving throw, DC equalling 8 + the attacking creature's to-hit bonus. On a failed save, a creature takes half of the normal attack's damage. On a successful save, the creature takes no damage.

T-Rex Tail (Normal)
+10 to hit, reach 10ft., one target. Hit: 20 (3d8 + 7) bludgeoning damage.

T-Rex Tail (Swipe)
10 ft. Flat Cone, Save DC 18, 10 (3d8 + 7) / 2 bludgeoning damage

Actions

Called Shots (Optional Rule)

From Galder's Gazetteer & Modified slightly
Once on a creature's turn if it has advantage and no disadvantage on an attack roll, it can roll one die instead of more to make a called shot. Choose a called shot from those described below. If it hit the target, the target takes only half damage from the attack but also suffers the first effect listed. If a creature is bloodied or hit with another of the same called shot before the start of its next turn, it needs to make a Con save, DC equaling 10 or the damage taken from the attack, whichever is higher. On a failed save, they also suffer the second effect.

Arm Shot

Aiming for a target's arms, hands, or other forelimbs in order to weaken its capabilities.
Creatures that are more than one size larger than the attacker cannot be affected by this called shot.

Bruised: Until the end of its next turn, the target is afflicted by one of the following until the end of its next its turn: cannot benefit from a shield, has disadvantage on weapon attacks with two hands, cannot use two-weapon fighting, has disadvantage on the next attack roll it makes using Strength or Dexterity, has disadvantage on Strength saving throws.
Broken: On its next turn, the target has disadvantage on attack rolls it makes using Strength or Dexterity

Head Shot

Aiming for a target's head or other processing body part in order to impair your foe.
Creatures that have multiple heads or are immune to the Stunned condition cannot by affected by this called shot.

Disorient: The target has disadvantage on ability checks and mental ability (Int, Wis, Charisma) saving throws until the end of its next turn.
Discombobulate: The target has disadvantage on ability checks and saving throws until the end of its next turn.

Leg Shot

Aiming for a target's legs, hips, knees, or other movement appendages in order to hinder its movement.
Creatures that are immune to being knocked prone or are incorporeal cannot be affected by this called shot.

Slowed: Until the end of its next turn, the target's speed is halved.
Stopped: The target either has disadvantage on Dexterity saving throws until the end of its next turn or is immediately knocked prone.

Charge

If a creature moves at least 20 feet in a straight line and then hits a target with a melee attack, it can use a bonus action to either Shove the target or deal additional damage equal to the creature's Strength modifier (minimum of 1). +1 is added to the total damage or the creature's Athletics check for every additional 10 feet it moves in the straight line.

Climb onto a Bigger Creature (DMG page 271)

If one creature wants to jump onto another creature, it can do so by grappling. A Small or Medium creature has little chance of making a successful grapple against a Huge or Gargantuan creature, however, unless magic has granted the grappler supernatural might.
As an alternative, a suitably large opponent can be treated as terrain for the purpose of jumping onto its back or clinging to a limb. After making any ability checks necessary to get into position and onto the larger creature, the smaller creature uses its action to make a Strength (Athletics) or Dexterity (Acrobatics) check contested by the target’s Dexterity (Acrobatics) check. If it wins the contest, the smaller creature successfully moves into the target creature’s space and clings to its body. While in the target’s space, the smaller creature moves with the target and has advantage on attack rolls against it.
The smaller creature can move around within the larger creature’s space, treating the space as difficult terrain. The larger creature’s ability to attack the smaller creature depends on the smaller creature’s location, and is left to your discretion. The larger creature can dislodge the smaller creature as an action—knocking it off, scraping it against a wall, or grabbing and throwing it—by making a Strength (Athletics) check contested by the smaller creature’s Strength (Athletics) or Dexterity (Acrobatics) check. The smaller creature chooses which ability to use.

Disarm (DMG page 271)

Once per turn, a creature can use a melee weapon attack to knock a weapon or another item from a target’s grasp. The attacker makes an attack roll contested by the target’s Strength (Athletics) check or Dexterity (Acrobatics) check. If the attacker wins the contest, the attack causes no damage or other ill effect, but the defender drops the item.
The attacker has disadvantage on its attack roll if the target is holding the item with two or more hands. The target has advantage on its ability check if it is larger than the attacking creature, or disadvantage if it is smaller.

Escaping Grappled and Restrained

Once you are grappled or restrained, you cannot use an acrobatics check to escape being grappled or restrained. However, if you are proficient in Athletics, you may use Dexterity instead of Strength for the Athletics check to escape being grappled.

Extra Opportunity Attacks

The Grapple and Shove attack variants can be taken in place of an attack when an opportunity attack is provoked.* When a creature in melee range of a hostile creature makes a ranged attack, the. If the attack hits, it can deal damage as normal or cause the ranged attack to have disadvantage. When a creature in melee range gets up from prone and does not use a bonus action to defend itself, they provoke an opportunity attack. *It is implied that this is the case in RAW, but Sage Advice contradicts that. However, in the words of Nick Fury, "I recognize the council has made a decision, but given that it's a stupid-ass decision, I've elected to ignore it."

Martial Attacks

From Galder's Gazetteer & Modified slightly
If you're able to make multiple attacks with the Attack action, you have the option to use one of these special attacks that replace one of the attacks made with the Attack action.

Arcing Slash

Replaces additional attack after a hit with a melee weapon that deals slashing damage
After hitting, choose any number of creatures in your reach beside the original target of the attack. If the original attack roll would hit the additional creatures, they take the slashing damage equal to your ability modifier that was used for the original attack plus any magic bonus the weapon grants to the damage roll. If the weapon has the Heavy property, it deals additional points of damage to the additional creatures equal to the minimum roll of any weapon dice.

Deep Stab

Replaces additional attack after a hit with a melee weapon that deals piercing damage
After hitting, you make a special attack roll against the same target at advantage. You don't add your damage modifier to the damage of this roll.

Staggering Bash

Replaces additional attack after a hit with a melee weapon that deals bludgeoning damage
The target takes additional damage equal to your damage modifier. If it your size or smaller, it needs to make a Strength or Dexterity saving throw equal to 8 + your attack modifier with the weapon. On a failed save, it is either knocked prone or knocked 5 feet in any direction of your choice.

Expert Shot

Replaces additional attack before an attack roll with a ranged or thrown weapon
You double your proficiency bonus for the attack.

Overrun (DMG page 272)

When a creature tries to move through a hostile creature’s space, the mover can try to force its way through by overrunning the hostile creature. As an action or a bonus action, the mover makes a Strength (Athletics) check contested by the hostile creature’s Strength (Athletics) check. The creature attempting the overrun has advantage on this check if it is larger than the hostile creature, or disadvantage if it is smaller. If the mover wins the contest, it can move through the hostile creature’s space once this turn.

Ready an Attack

If a creature has the Multiattack trait, they can forgo an attack to take the Ready action, with the one attack being the triggered when the condition is met.

Shield Bash

As a bonus action is a creature is wielding a shield, they can make an attack with it. A shield, when used this way, counts as a martial weapon in terms of proficiency, uses Strength, and deals 1 + the creature's strength modifier bludgeoning damage on a hit.

Shove Aside (DMG page 272)

With this option, a creature uses the special shove attack from the Player’s Handbook to force a target to the side, rather than away. The attacker has disadvantage on its Strength (Athletics) check when it does so. If that check is successful, the attacker moves the target 5 feet to a different space within its reach.

Sprint

A creature can use up its entire turn and reaction to move up to four times its movement speed in one direction, making up to two 45% turns that must be in the general direction that the creature is going. The creature has to make a DC 10 Dexterity (Acrobatics) check to keep its balance if it moves more than three times its movement speed. It may make a Strength (Athletics) check, and move an additional number of feet equal to that. If the creature has something such as the Cunning Action trait that allows it to take the Dash action as a bonus action, it can use that to achieve up to 5 times its movement speed. A creature can Sprint a number of times in a row equal to your Constitution Modifier + 1 until it has to make Constitution saving throws or be subjected to gaining a level of exhaustion, starting DC 15. The DC goes up by 1 for every success (ex. 3 successes would then be DC 18). If a creature has a negative Constitution modifier, it cannot take this action. All levels of exhaustion gained in this way can be cleared by a short or long rest.

Tumble (DMG page 272)

A creature can try to tumble through a hostile creature’s space, ducking and weaving past the opponent. As an action or a bonus action, the tumbler makes a Dexterity (Acrobatics) check contested by the hostile creature’s Dexterity (Acrobatics) check. If the tumbler wins the contest, it can move through the hostile creature’s space once this turn.

Effects & Traits

Altered & Additional Conditions

Exhaustion

Altered
Creatures take a penalty to attack rolls, ability checks, saving throws, and save DCs equal to the number of exhaustion points it has, and its speed is reduced by 5 times the same amount. If a creature has a number of exhaustion points equal to or more than half their Constitution score, they die.

Intoxicated

Additional

Intoxicated creatures gain a number of temporary hit points equal to the amount of hit dice it has for as long as they are intoxicated. A creature additionally has a degree of disadvantage on attack rolls, ability checks, and saving throws for each level of Intoxication a creature has. When the Intoxicated condition ends, a creature gains levels of exhaustion equal to its Intoxication level. Any defenses, vulnerabilities, or effects relating to poison damage or the poisoned condition a creature possesses apply for resisting Intoxication.

Suprised

Additional A suprised creature is stunned. This condition ends when the creature's first turn in a combat ends.

Stunned

Altered

A stunned creature doesn't add their Dexterity modifier to their AC. Everything else about the condition is the same.

Wounded

Additional; optional at the DM's discretion)
At the end of a creature's turns, for every wound the creature has, they take 1d4 damage. The damage type is the same as the damage dealt by the trigger. One wound is healed every 5 hit points the creature gains or if a creature successfully uses an action to make a DC 15 Wisdom (Medicine) check. The check is with advantage if the creature is using a medicine kit. A creature must have a distinct form capable of suffering the damage to be affected. The player who causes the condition is responsible for recalling the subsequent damage rolls in a timely manner.

Assassination

If a suprised creature is hit with an attack, the attacker rolls another attack normally (not with disadvantage or advantage), called an assassination roll. If the assassination roll would hit the creature, the damage the creature takes is doubled; on a critical hit, the damage is tripled. If the assassination roll misses, the attack deals damage as normal.

Cleaving Through Creatures (DMG page 272)

When a melee attack reduces an undamaged creature to 0 hit points, any excess damage from that attack might carry over to another creature nearby. The attacker targets another creature within reach and, if the original attack roll can hit it, applies any remaining damage to it. If that creature was undamaged and is likewise reduced to 0 hit points, repeat this process, carrying over the remaining damage until there are no valid targets, or until the damage carried over fails to reduce an undamaged creature to 0 hit points.

Countering the Counter

Abjuration is both the most stable and the most volatile school of magic. I love it for the contradiction that it poses.
-Bipbap the Magnificent

If you counterspell another counterspell, roll on the Wild Magic Surge table a number of times equal to the counterspells cast, with each creature or effect casting counterspell being the center/target of one of the wild magic surges.

Critical Damage (Optional)

When a creature scores a critical hit* against a targeted creature, an extra effect happens determined by the damage type. If the damage source has two or more damage types, the creature may choose only one. A targeted creature must have a form capable of suffering the effects for the extra effect to take place. A creature immune to certain conditions or the damage type doesn't suffer these effects. *At the DM's discretion, if a creature fails a save a saving throw by 15 or more against any of these types and its not resistant or immune to the damage, it can be subject to the corresponding effect as well.

Normal

Bludgeoning: Staggering

The targeted creature is pushed up to 5 feet away and knocked prone, provided the target is no more than one size larger than the attacking creature. Until the end of its next turn, the targeted creature doesn't add its proficiency bonus to saving throws and d20 rolls that it usually does. Immunity to the Stunned condition negates this effect.

Piercing: Impaling

The targeted creature gains a wound and is wounded, and gains an additional wound for every 10 piercing damage it took from the initial damage.

Slashing: Lacerating

The targeted creature gains a wound and is wounded, but instead of the normal DC of 15, its 15 or 8 + the attacking creature's to-hit modifier, whichever is higher, or the targeted creature needs to regain a number of hit points greater than or equal to the attacker's to-hit bonus to end the wounded condition.

Elemental

Acid: Corroding

The targeted creature gains one wound and is wounded, and gains an additional wound for every 10 acid damage it took from the initial damage.

Cold: Freezing

The targeted creature's movement speed is reduced by 10 + half the cold damage dealt, and it has disadvantage on any attack roll, ability check, or saving throw made until the end of its next turn. This effect ends early if the creature takes 5 or more fire damage.

Fire: Burning

The targeted creature gains one wound and is wounded, and gains an additional wound for every 10 fire damage it took from the initial damage. This effect ends early if the creature takes 5 or more cold damage.

Lightning: Shocking

The targeted creature's movement speed is reduced by 10 + half the lightning damage dealt, and it has disadvantage on any attack roll, ability check, or saving throw made until the end of its next turn. This effect ends early if the creature gains 5 or more hit points.

Poison: Poisoning

The target is automatically poisoned. This lasts until the end of the creature's next turn or it regains 5 or more hit points. Immunity to the Poisoned condition negates this effect.

Thunder: Disorienting

The targeted creature has disadvantage on ability checks, attack rolls, and saving throws until the end of its next turn. If it moves 5 or more feet, it must make a Dexterity saving throw (DC equalling half the initial thunder damage dealt) or drop prone. This effect ends early if the creature regains 5 or more hit points. Immunity to the Stunned condition negates this effect.

Otherworldly

Force: Disintegrating

The targeted creature gains one wound and is wounded. The DC to stop the wound is 15 or half the force damage dealt.

Psychic: Confusing

The targeted creature has disadvantage on ability checks, attack rolls, and saving throws until the end of its next turn, and has its speed reduced by 10 + half the initial psychic damage. This effect ends early if the creature regains 5 or more hit points.

Radiant: Atomizing

The targeted creature gains one wound and is wounded. The DC of the medicine check to stop the wound is 15 or half the radiant damage dealt. The effect ends if the creature takes 5 or more points of necrotic damage.

Necrotic: Decaying

The targeted creature gains one wound and is wounded. The DC of the medicine check to stop the wound is 15 or half the necrotic damage dealt. The effect ends if the creature takes 5 or more points of radiant damage.

Dropping to 0 and Death

Staggered & Death's Door

When a character is reduced to 0 hit points but is not killed outright, it is Stunned until the start of its next turn, gains one level of Exhaustion, and is Staggered. Whenever a Staggered creature takes damage, it gains one level of Exhaustion. On a critical hit, it suffers two levels of Exhaustion. If the creature regains any hit points, the Staggered condition ends. If the damage accumulated while staggered is at or over the character’s maximum hit points, they die. Up to 2 levels of Exhaustion gained while Staggered are cleared at the end of a Long Rest if they have more than 0 hit points at the end of the rest.

Returning from Death

Roll a d20 and add a bonus equal to half the level spellcasted to bring you back to life to the roll. Take a -1 penalty for each time you've died previously. Consult the table below.

Roll Total	Result
<10	Your death is permanent and cannot be reversed by any means short of a Wish spell or a Divine Intervention.
10-15	You are partially restored to life. You lose all your memories but retain your statistics. Change your species to Reborn.
16+	You are successfully restored to life.

Divine Intervention and True Resurrection can only be attempted once each on a creature before its soul is lost to the afterlife.

Fear: Fight or Flight

When a creature come under the Frightened condition, it may choose one of three options at the start of its fear. Choose the best one in terms of how it would act, but if it fails the saving throw to not be afraid by 5 or more, then it has to choose Flight. If it fails the save by 15 or more then it has to choose Frozen.

Fight

The only thing a creature can do is try to kill or destroy the source of its fear. It must use its most basic, natural attack or weapon (such as a bear's claw, or a guard's spear) and its entire turn to attempt to kill or destroy the object of its fear. Its movement must be purely focused on present offense, instead of defense or future offense. It suffers a penalty to its attack rolls equal to the difference between the DC and its roll.

Flight

The creature must use its action or bonus action to Dash away from the creature with the intent. If the creature has teleportation magic or something that would achieve a similar effect, it may use that but is not forced to.

Frozen

The creature is Stunned. The creature can make a saving throw equal to the DC - 10 at the start of its turn, ending the Frozen effect on itself on a success. Whenever the creature This success can only move it to Fight or Flight, not end the Frightened condition on itself.

Flying Creatures

In flight, flying creatures must make concentration saving throws when they take damage (as if they were concentrating on a spell, but it doesn’t count as concentrating on a spell) or get knocked out of the sky. A creature that is knocked from flight that falls 20 feet or more may use its reaction to make a DC 15 Dexterity saving throw to stop falling and fly in place until their next turn.

Health into Magic

A creature can cast a spell up to sixth level that they know. Immediately after the spell is cast, they gain levels of exhaustion equal to the spell's level. Creatures immune to the exhuasted condition cannot do this.

Massive Damage (DMG page 273)

When a creature takes damage from a single source equal to or greater than half its hit point maximum, it must succeed on a DC 15 Constitution saving throw or suffer a random effect determined by a roll on the System Shock table. This only takes effect after 5th level. For example, a creature that has a hit point maximum of 30 must make that Constitution save if it takes 15 damage or more from a single source.

1d10	Effect
1	The creature drops to 0 hit points
2-3	The creature drops to 0 hit points but is stable
4-5	The creature is stunned until the end of its next turn
6-7	The creature can't rake reactions and has disadvantage on attack rolls and ability checks until the end of its next turn.
8-10	The creature can't take reactions until the end of its next turn.

Mount Changes

Mounting

Once during your move, if a willing creature is one size larger than you, you mount it with 15 feet of movement. If a willing creature is two or more sizes larger than you, you mount it with 30 feet of movement.

Controlling a Mount

A controlled mount can take the Attack action as well as the Dash, Disengage, and Dodge action.

Rest

Resting is refreshing, especially after a long or exhausting journey or day.

Quality of Long Rest	Effect
Wretched	DC 13 Con save or no exhaustion is cleared -2 to Charisma checks and saving throws until next long rest
Squalid	DC 10 Con save or no exhaustion is cleared -1 to Charisma checks and saving throws until next long rest
Poor	DC 5 Con save or no exhaustion is cleared
Modest	None
Comfortable	Recover 75% of your hit dice instead of 50%
Wealthy	Recover 75% of your hit dice instead of 50% Gain temp. HP equal to total hit dice
Aristocratic	Recover 100% of your hit dice instead of 50% Gain temp. HP equal to total hit dice Clear 2 levels of exhaustion instead of 1

Trained Conditioning

The armor that a creature is proficient with counts as weighing half as much as its normal weight when worn for the purposes of encumbrance.

Two-Handed Weapon

Attacking with a two-handed weapon allows a creature to add half its damage modifier (rounded up) to the damage (i.e. 16 mod = +3 bonus, 3/2 = 1.5, rounded up = 2 extra damage) if it's proficient with the weapon. The Great Weapon Fighting Style allows you to treat a 1 on the damage roll as a 2.

Two-Weapon Fighting

If a creature has the Multiattack trait, it can make an offhand attack as a part of their attack action, and a second one as their bonus action (applies to Monk's Martial Arts). If you have three or more base attacks, you can make two offhand attacks as your bonus action instead of one. If you have the Two-Weapon fighting style, you can draw or stow two one-handed weapons when you would normally be able to draw or stow only one.

Underwater Combat

In my mortal life, I was both terrified and fascinated by the depths. Now that I am something greater, I am even more acutely interested by the depths and scared no longer.
-Farai

Ranged weapons deal half damage underwater. They are harmless after 10 feet.

Fire

The range and AoE of fire-related spells are both halved. Nonmagical, normal fire is extinguished instantly if submerged. Submerged creatures have advantage on saving throws against fire spells (such as fireball) in addition to the normal fire resistance.

Lightning

The range and AoE of lightning-related spells are both doubled. Submerged creatures have disadvantage on saving throws against lightning spells(such as lightning bolt)

Weapons In General

If you have a negative strength or dexterity modifier, you take a penalty to the attack and damage rolls made with weapons equal to the modifier (i.e. longsword; +2 prof., +3 str., -1 dex. = +4 to attack). This doesn't apply to daggers.

Adjustments to Feats

These are feats that feel lackluster and in dire need of updating, or just adjustments that I feel balance the feat. Any ability score increases can't increase an ability score over 20.

Alert

Addition

+1 to Wisdom or Dexterity

Armor Training and Mastery

The feats giving proficiency and mastery of armor feel lackluster

Heavy Armor Master

Adjustment
While you are wearing heavy armor and aren't incapacitated, bludgeoning, piercing, and slashing damage that you take is reduced by your proficiency bonus.

Lightly Armored

Addition
You gain proficiency with shields.

Medium Armor Master

Addition
+1 to Strength or Dexterity, to a maximum of 20.

Artificer Initiate

Addition
Prerequisite: Intelligence or Wisdom 13+
Increase your Intelligence or Wisdom by 1, up to a maximum of 20. You gain access to one of the following infusions: Enhanced Weapon, Armor of Magical Strength, Mind Sharpener, Repeating Weapon, Returning Weapon. You can swap one for another on a long rest.

Athlete

Addition
You count as if you were one size larger for the purposes of determining your carrying capacity and other related things.

Crossbow Expert

Adjustment

You only ignore the loading property if you have a hand free to reload it.
You must use a melee weapon to attack with a hand crossbow as a bonus action.

Dual Wielder

Adjustment

You gain a +1 bonus to AC while wielding a light weapon in each hand.
You can use one non-light one-handed melee weapon.

Dungeon Delver

Addition

+1 to Intelligence or Wisdom to a maximum of 20
You may take the Search action as a bonus action.
You gain darkvision to a range of 30 feet. If you already have darkvision, your darkvision increases by 30 feet, to a maximum of 90 feet. Dim light doesn't impose disadvantage on Wisdom (Perception) checks out in this range.

Eldritch Adept

Addition

You learn one warlock cantrip of your choice

Increase one ability score by 1 to a maximum of 20

This feat can be taken multiple times

Gift of the Chromatic/Metallic Dragon

Addition

Chromatic: Increase your Constitution score by 1, to a maximum of 20
Metallic: Increase your Intelligence, Wisdom, or Charisma score by 1, to a maximum of 20

Grappler

Adjustment

+1 to Strength, Dexterity, or Constitution, to a max of 20
Grapple and pin are bonus actions, and creatures smaller than you have disadvantage on checks to escape your grapple and against your pin.
When a creature you are grappling attempts to break their grapple and fails, you can use your reaction to make a melee attack against them.
You can grapple creatures 1 size larger than normal.

Great Weapon Master & Sharpshooter Adjustments

Adjustment
You don't take a -5 penalty to the attack roll for a +10 bonus to the damage with these feats, you instead take a penalty equal to your proficiency bonus to add twice your proficiency bonus to the damage. Great Weapon Master grants a +1 to Strength, Sharpshooter grants a +1 to Dexterity.

Inspiring Leader

Addition

Increase your Charisma score by 1, to a maximum of 20
While the temporary hit points last, creatures have advantage on saving throws to resist charms or frightened

Mage Slayer

Adjustment

Increase your Strength or Dexterity score by 1, to a maximum of 20
When a creature within melee reach that you can see casts a spell or uses a spell-like ability, you can use your reaction to make a melee attack against that creature. On a hit, the creature has to make a Constitution saving throw with a special bonus equal to the spell that they were attempting to cast’s level (or an appropriate equivalent bonus for the spell-like ability of the DM's discretion; a creature's proficiency bonus is a good place to work from), the DC is 8 + the damage dealt with the attack. On a failed save, the caster fails to cast the spell, but the spell slot is not expended. On a success, they cast the spell as normal.
Instead of having advantage on saving throws against spells cast from creatures within 5 feet, you have advantage on saving throws against spells cast by creatures you can see within a number of feet of you equal to 10 * your proficiency bonus.

Magic Initiate

Addition
Your Intelligence, Wisdom, or Charisma increases by 1. The score is determined by the casting ability of the class you learned magic from.

Metamagic Adept

Adjustment
You gain a number of Metamagic points equal to your proficiency bonus.

Mobile

Addition
Increase your Strength or Dexterity score by 1 to a maximum of 20.

Mounted Combatant

Addition

Prerequisite: proficiency in Animal Handling
Increase your Strength or Dexterity by 1 to a maximum of 20
You only need to use 5 feet of movement to mount a willing creature

Observant

Addition
You gain advantage on Perception and Investigation checks.

Polearm Master

Adjustment

The feat functions as normal, but you must be wielding the polearm in two hands to use the bonus action attack that the feat provides.

Poisoner

Adjustment

The DC equals 8 + your proficiency bonus + either your Intelligence or Wisdom modifier, and the creature takes half damage on a successful save, instead of none
Any damage roll you make involving poison ignores resistance
You can create a number of potent poisons equal to yoour proficiency bonus with one workday of work and 5 gp worth of materials per dose.

Special Poison. Once applied to a weapon, the poison retains its potency for 1 minute or until you hit with the weapon or ammunition. When a creature takes damage from the coated weapon, it must succeed a Constitution saving throw (DC equals 8 + your Intelligence or Wisdom modifier + your proficiency bonus) or be poisoned for one minute and take a number of d6s of poison damage equal to your proficiency bonus, taking half damage and not being poisoned on a successful save. A creature must repeat the Constitution saving throw at the start of each of its turns. After three successful saves, the poisoned condition ends.

Ritual Caster

Addition

Increase your Intelligence, Wisdom, or Charisma by 1 to a maximum of 20
Each time you gain a level, you gain another ritual from the chosen list

Savage Attacker

Adjustment

Increase Str or Con to a maximum of 20
Once per turn, you can add an extra weapon die (up to a d8) to the damage of an attack (i.e. longsword is 2d8 + str, but a greatsword is d12 + 1d8 + str).
When you score a critical hit or reduce a creature to 0 hit points, you can use a bonus action to attempt to frighten another creature within 30 feet of you. The creature must succeed on a Wisdom saving throw with a DC equal to 8 + your proficiency bonus + your Strength or Charisma modifier

Sentinel

Adjustment

When you hit a creature no more than one size larger than you with an opportunity attack, its speed is reduced to 0.

Shield Master

Addition & Adjustment

+1 to either Str or Dex to a max of 20
You can shield bash as a part of your action

Tavern Brawler

Replacement

+1 Strength, Dexterity or Constitution max 20
Your unarmed strikes use a d4 for damage
Your improvised weapons use a d6 for damage and, if they're big enough, gain the versatile (d8) property
Your speed isn't halved by carrying a grappled creature who is the same size or smaller
When you hit a creature with an unarmed strike or an improvised weapon on your turn, you can use a bonus action to attempt to grapple the target.

Tough

Addition
Increase your strength or dexterity by 1 to a maximum of 20

Weapon Master

Addition
Choose three weapons in which you are proficient. Those weapons gain a +2 to attack rolls.

War Caster

Addition
You gain a +1 to Con score or mental ability score, max 20.