All the different mechanics that offer rerolls/replacement results [closed]

Question

Can we get an exhaustive list of ways to reroll, or change the result of, a die?

I'm currently only concerned with yourself or your allies rolls.

Answer 1

Racial Traits

• Lucky (Halfling)

  When you roll a 1 on the d20 for an attack roll, ability check, or saving throw, you can reroll the die and must use the new roll.

Class Features

Barbarian

• Indomitable Might

  [...] if your total for a Strength check is less than your Strength score, you can use that score in place of the total.

• Zealot Barbarian's Fanatatical Focus

  Allows you to reroll failed saving throws

Bard

• Eloquence Bard's Silver Tongue

  Allows you to replace the d20 roll on specific ability checks you make with a 10

Druid

• Stars Druid's Dragon Starry Form

Allows you to replace the d20 roll on specific ability checks you make with a 10

Fighter

• Indomitable

  [...] you can reroll a saving throw that you fail. If you do so, you must use the new roll [...]

• Arcane Archer's Curving Shot

  Allows you to reroll missed attack rolls

Monk

• Martial Arts

  [...] You can roll a d4 in place of the normal damage of your unarmed strike or monk weapon. [...]

• Diamond Soul

  [...] whenever you make a saving throw and fail, you can spend 1 ki point to reroll it and take the second result.

• Kensei Monk's Unerring Accuracy

  Allows you to reroll missed attack rolls

Paladin

• Glory Paladin's Living Legend

  Allows you to reroll failed saving throws

Rogue

• Reliable Talent

  [...] Whenever you make an ability check that lets you add your proficiency bonus, you can treat a d20 roll of 9 or lower as a 10.

• Stroke of Luck

  [...] if you fail an ability check, you can treat the d20 roll as a 20 [...]

• Inquisitive Rogue's Ear for Deceit

  Allows you to replace the d20 roll on specific ability checks you make with an 8

• Swashbuckler Rogue's Master Duelist

  Allows you to reroll a missed attack roll with advantage

Sorcerer

• Empowered Spell Metamagic

  [...] you can spend 1 sorcery point to reroll a number of the damage dice up to your Charisma modifier [...]

• Divine Soul Sorcerer's Empowered Healing

  Allows you to reroll dice rolled for healing spells

Wizard

• Chronurgy Wizard's Chronal Shift

  Allows you to force a reroll of an attack roll, ability check, or saving throw

• Divination Wizard's Portent

  Allows you to replace an attack roll, saving throw, or ability check.

Fighting Styles

• Great Weapon Fighting (Fighter and Paladin)

  When you roll a 1 or 2 on a damage die for an attack you make with a melee weapon that you are wielding with two hands, you can reroll the die and must use the new roll, even if the new roll is a 1 or a 2. [...]

Feats

• Durable

  Increases the minimum hit points restored when spending Hit Dice

• Savage Attacker

  Allows you to reroll melee damage rolls

• Elemental Adept (Spellcaster)

  Allows you to treat 1's as 2's on certain spell damage rolls

• Bountiful Luck (Halfling)

  Allows allies to reroll 1's on ability checks, attack rolls, and saving throws

• Second Change (Halfling)

  Allows you to force an attack that hits you to be rerolled

• Elven Accuracy (Elf or Half-Elf)

  Allows you to reroll certain attack rolls if you have advantage

• Flames of Phlegethos (Tiefling)

  Allows you to reroll 1's on dice when rolling fire damage for spells

Spells

• wish

  [...] You undo a single recent event by forcing a reroll of any roll made within the last round (including your last turn). [...]

• glibness

  [...] when you make a Charisma check, you can replace the number you roll with a 15. [...]

Magic Items

• Any magic item that can cast wish

• Ring of Evasion

  [...] When you fail a Dexterity saving throw while wearing it, you can use your reaction to expend 1 of its charges to succeed on that saving throw instead.

• Luck Blade

  [...] If the sword is on your person, you can call on its luck (no action required) to reroll one attack roll, ability check, or saving throw you dislike. [...]

• Dragon Masks

  Allow you to succeed on failed saving throws

• Clockwork Amulet

  Allows you to forgo an attack roll and treat the d20 as having rolled a 10

Answer 2

An honorable mention would be "Law of Averages" while on the plane Mechanus, which treats all damage rolls as automatically ½ maximum (2d6+5 is always 11, because each d6 is automatically treated as a 3).