Outside of the roleplaying and how to play aspect, the basic rules a player needs are as follows: Adventuring

Your character has six ability stats that identify their different physical or mental traits. Characters may devote their attention to various tasks while adventuring.
The max for each is 20. Each number will also have a +Bonus, called a Modifier, you add this to rolls. Success may be determined on passive or active checks according to DM.
There are 18 skills that each map to an ability score. The character looks out for any noticeable threats
Watch for Threats
Any action outside of combat will map to one of these skills, this is called an Ability check; your DM will tell you when and what to roll. based on their Wisdom (Perception).
All action rolls are D20. Higher is better. All rolls except damage are D20 + Stat Modifier + Proficiency bonus (if applicable) The character can try to prevent the group from
Navigate
Two primary ways that rolls become easier or harder. They are called Advantage and Disadvantage. becoming lost, based on their Wisdom (Survival).
If you have Advantage you roll two dice and take the higher number. The character can draw a map that records the
If you have Disadvantage you roll two dice and take the lower number. Draw a Map group’s progress and helps the characters get back on
Advantages and Disadvantages cannot stack, but they can counter each other out. course if they get lost. No ability check is required.
To play, decide what your character would do and narrate your action. A character can follow the tracks of another creature,
Track
Your DM and other Players will interact to determine the proper ability check (or not) to resolve the outcome. based on their Wisdom (Survival)
When a player role-plays their character, as defined by its traits, background, etc. well, the DM may allot them with an The character can keep an eye out for ready sources
Forage
inspiration bonus, which grants advantage to one roll. of food and water, based on their Wisdom (Survival).
Advantage Combat
On your turn, you can move a distance up to your speed and take one action.
Attacks Against Targets Blinded, Paralyzed, Prone (@ 5ft), Restrained, Stunned, Unconscious
You can also interact with one object or feature of the environment for free, during either your move or your action.
Attacking While Hidden, Invisible, Helped Actions In Combat
Disadvantage Make a Melee or Ranged attack
Attack
Invisible Target, Blinded, Frightened, Poisoned, Stunned, Squeezing, On Hit, deal Weapon + Ability Modifier damage to the target
Attacks When
Long Range @ 5 ft Range, Long Range @ Prone Target > 5ft Range When attacking, a roll of 20 is a Critical Hit which always hits, regardless of modifiers
Ability Checks Frightened, Poisoned Critical Hit/Miss For Critical damage, roll damage dice twice, add modifiers once
A roll of 1 is always a miss, regardless of modifiers. Additional misfortune may occur according to DM.
Dex Saves Squeezing
Cast a Spell Cast a spell with 1 action casting time
Cover Damage Resistance & Vulnerability
Dash Double movement of your current speed
Half Cover +2 AC/Dex Saves Resistance & Vulnerability are applied after modifiers
Disengage Your movement does not provoke opportunity attacks for the rest of your turn
Damage
Three Quarter +5 AC/Dex Saves Take ½ dmg from resisted dmg types Creatures attacks against you are at a disadvantage until your next turn
Resistance Dodge
You get advantage on Dexterity saving throws. Ends if incapacitated
Cannot be targeted Damage
Full Take 2x dmg from vulnerable dmg types Make a Str (Athletics) check against Defender's Str (Athletics) or Dex (Acrobatics)
directly Vulnerability
Grapple On success, you hold on to an opponent to prevent them from moving
Vision & Light Resting
You may move a grappled opponent at half your speed, unless the opponent is 2 sizes smaller.
At least 1 hour. Optional healing of
Dim light, Disadvantage Attempt to escape being held
Lightly Obscured Short Rest (1 hit die + Constitution Modifier) Escape (Grapple)
on Wis (Perception) Escapist’s Str (Athletics) or Dex (Acrobatics) against Grappler’s Str(Athletics)
per character level.
Help Creature you aid gets advantage on ability checks, or attacks against a creature within 5 ft of you
At least 8 hours. Regain hit dice up to 1
Darkness, creatures Make a Dex (Stealth) check against Wisdom (Perception) of creature
Heavily Obscured Long Rest per 2 character levels. Cannot benefit Hide
suffer Blinded condition On success, you are an Unseen attacker and have advantage on attacks
from more than 1 long rest per 24 hours.
Death Prepare a Reaction for a particular circumstance, which you can take later in the round once triggered
Ready
If the trigger does not occur, you lose your action for the round
Instant Death If remaining damage after zero >= max HP, the character dies instantly
Search Wis (Perception) or Int (Investigate) ability check to find something
Unconscious If creature doesn't die instantly, they are at 0 HP and unconscious and dying
Make a Str (Athletics) check against Defender's Str (Athletics) or Dex (Acrobatics)
Roll a D20 to determine success or failure Shove
Death Saving On success, you knock the Defender prone or 5ft away
On the 3rd Success, the character becomes stable
Throws Use an Object Use an object that requires an action for its use
On the 3rd Failure, the character dies
Extra Actions
A roll of 10 or above is a success
Success Various class features, spells, and other abilities let you take an additional action on your turn called a bonus action.
Rolling a 20, the character regains 1 hp and wakes up
You may only take one bonus action per turn.
A roll of 9 or below is a failure
Fail If attacking with a light melee weapon that one hand, use a bonus action to attack with a different light
Rolling a 1 counts as two failures
Two-Weapon Fighting melee weapon that in the other hand. Ability modifiers are not added to the damage of the bonus
Damage While attack, unless that modifier is negative.
Being hit while unconscious counts as 1 failure, critical hits count as 2 failures
Downed Certain special abilities, spells, and situations allow you to take a special action called a reaction; an instant response to a trigger.
A stable character remains unconscious, but is no longer dying When you take a reaction, you can’t take another one until the start of your next turn.
Stable
The character will regain 1 HP after 1d4 hours if not healed before that time Opportunity Attack When a hostile creature you see leaves your reach
First Aid A dying creature may be stabilized from a successful DC10 Wis (Medicine) check (Melee Only) Disengage prevents OA, as does teleport, or forced movement
 Conditions General Spell Casting Mechanics
Creature can’t see and automatically fails any ability check that requires sight. Spell Save DC 8 + Proficiency Bonus + Ability Modifier
Blinded
Attack rolls against the creature have advantage, and the creature’s attack rolls have disadvantage. Spell Attack Modifier Proficiency Bonus + Ability Modifier
Creature can't attack the charmer or target the charmer with harmful abilities or spells. Spell casting in armor Requires proficiency in that armor. Wearing armor without proficiency prevents spellcasting
Charmed
The charmer has advantage on any ability check to interact socially with the creature. Taking damage while casting a spell forces a Constitution saving throw of the higher of DC 10
Concentration
Deafened Creature can’t hear and automatically fails any ability check that requires hearing. or half the damage received. Failing the save interrupts the spell.
A frightened creature has disadvantage on ability checks and attack rolls while the source of fear is Cones extend from their PoE (Point of Origin), up to their given AoE.
Frightened
within Line of Sight. The creature also cannot willingly move closer to the source of its fear. Cube PoE is anywhere along any face of the cube, the size of the cube is the length of a side.
Creature’s speed becomes 0, and it can't benefit from any bonus to its speed. Cylinders PoE is at the center of a circle of a radius given in the spell's description and their
Grappled The condition ends if the grappler is incapacitated. AOE effect extends out from the origin to the edges of said circle.
The condition also ends if an effect removes the grappled creature from the reach of the grappler. (Areas of Effect) Lines extend from the PoE, up to their length, with an area covered by their listed width.
Incapacitated Creature can’t take actions or reactions. Spheres effects extend a set distance - their radius - from their PoE.
Creature is impossible to see without the aid of magic or a special sense. For hiding, the creature is Cylinders and Spheres include their PoE in their effect.
Invisible heavily obscured. The creature’s location can be detected by any noise it makes or any tracks. Cones, Cubes and Lines do include their PoE in their effect unless otherwise specified.
Attack rolls against the creature have disadvantage, and the creature’s attack rolls have advantage. Weapons and Equipment
Creature is incapacitated and can’t move or speak.
The creature automatically fails Strength and Dexterity saving throws. Equipment cost and stats may be located from basic rules Pg 44
Paralyzed
Attack rolls against the creature have advantage.
Wearing armor without proficiency prevents spell casting, and results in disadvantage on
Any attack that hits the creature is a critical hit if the attacker is within 5 feet of the creature. Armor Proficiency
ability checks, saving throws, and attack rolls that use Str or Dex
Creature is transformed, along with any nonmagical object it is w earing or carrying, into a solid
inanimate substance (usually stone). Its weight increases by a factor of ten, and it ceases aging. Armor Requirements Heavy armors have a Str requirement, which if not met, results in a 10 foot speed penalty
The creature is incapacitated, can’t move or speak, and is unaware of its surroundings. Choose either Str or Dex for the attack and damage rolls.
Petrified Attack rolls against the creature have advantage. Finesse Weapons
Must use the same stat for both rolls
The creature automatically fails Strength and Dexterity saving throws.
The creature has resistance to all damage. Heavy Weapons Small size characters and creatures suffer disadvantage when using heavy weapons.
The creature is immune to new poison and disease; existing infection is suspended, not neutralized. You can fire only one piece of ammunition from a weapon with this property when you use
Poisoned Creature has disadvantage on attack rolls and ability checks. Loading property
an action, bonus action, or reaction, regardless of the # of attacks you can normally make.
Creature’s only movement option is to crawl, unless it stands up (no longer Prone).
Reach property Add 5 feet to character’s melee attack range
Standing up from Prone costs ½ the creature's movement.
Prone
The creature has disadvantage on attack rolls. Thrown property May use these for melee or ranged attacks. Both ranged and melee use same abilities
Attack rolls have advantage if the attacker is within 5ft. Otherwise, attack roll has disadvantage.
Versatile property Can be used one- or two-handed. The number in parentheses indicates 2-handed attack dmg
Creature’s speed becomes 0, and it can’t benefit from any bonus to its speed.
Restrained Attack rolls against the creature have advantage, and the creature’s attack rolls have disadvantage. Silvering a Weapon Costs 100gp per weapon or 10 pieces of ammunition.
The creature has disadvantage on Dexterity saving throws. Provides bonus dmg to creatures with resistance to or immunity from nonmagic weapons.
Creature is incapacitated, can’t move, and can speak only falteringly. Donning Armor
Stunned The creature automatically fails Strength and Dexterity saving throws.
Attack rolls against the creature have advantage. Category Don Doff
Creature is incapacitated, can’t move or speak, and is unaware of its surroundings. Light Armor 1 min 1 min
The creature drops whatever it’s holding and falls prone. Medium Armor 5 min 1 min
Unconscious The creature automatically fails Strength and Dexterity saving throws.
Attack rolls against the creature have advantage. Heavy Armor 10 min 5 min
Any attack that hits the creature is a critical hit if the attacker is within 5 feet of the creature Shield 1 action 1 action
Exhaustion Exchange Rates
Level Effect Coin CP SP EP GP PP
1 Disadvantage on ability checks
Copper (cp) 1 1/10 1/50 1/100 1/1000
2 Speed halved
3 Disadvantage on attack rolls and saving throws Silver (sp) 10 1 1/5 1/10 1/100
4 Hit point maximum halved Electrum (ep) 50 5 1 ½ 1/20
5 Speed reduced to 0
Gold (gp) 100 10 2 1 1/10
6 Death
Level increases as specified in the causing effect. Platinum (pp) 1000 100 20 10 1
Creature suffers the effects of all lower levels
Finishing a long rest reduces a creature's exhaustion level by 1, if the creature is not hungry or thirsty.