Your turn: 1 each: Move, Interact, Action, Bonus Action, Reaction

Move: Up to speed, can split within any actions, even between attacks. Difficult terrain, climb, swim, crawl costs double. Jump needs 10ft running start or halved. Jump upto your STR score in feet horizontal or jump up to 3 + STR mod vertical.

Actions
Attack: d20, on 20 always hit and crit, on 1 always miss. Proficiency + STR/DEX mod. If >= AC, hit. Roll damage + STR/DEX mod. If crit, roll again and add.
Cast Spell: As Attack, but always proficient, add spellcasting ability mod instead, but not to damage.
Dash: Double your speed this turn.
Disengage: Your movement does not provoke opportunity attacks.
Dodge: Gain Advantage on DEX save. Attacks against you have disadvantage. Cannot have 0 speed or be incapacitated.
Grapple: Their Str or Dex save (their choice) vs your DC 8+Str+Prof. Same for escape action. Costs 1 unarmed attack. Cannot be 2 sizes bigger than you, must be within reach.
Help: Target gains advantage on next ability check if you're proficient, or attack if you're within 5ft, before next turn.
Hide: Stealth to become invisible.
Improvise: Any other action. Break down door, intimidate, throw jar, etc.
Ready: Ready an Action with a trigger. When trigger occurs, use Reaction to perform.
Search: Make a Perception or Investigation check (DM choice).
Shove: As Grapple, but success knocks target prone or push 5 feet.
Stabilize: Use Healer's Kit or Medicine check DC10 to stabilize dying target.

Interactions: Draw/sheathe item, open/close door, get from pack, pick up, hand item to someone, throw lever/switch, turn key in lock.

Disadvantage: Roll twice, use lower.
Blind: Fail sight checks. Disadvantage on attacks. Attackers have Advantage.
Charmed: Cannot attack or target charmer with harmful effects. Has Advantage with social checks on you.
Deaf: Fail any check using hearing.
Frighten: Disadvantage on actions while you can see source of fright. Can't willingly move towards them.
Grappled: Speed is 0. Disadvantage on attacks on anyone but grappler. Can be moved (2x cost). Ends if grappler incapacitated, past reach, or escape.
Incapacitated: Cannot take any kind of action. Lose concentration. No speech. Always surprised.
Invisible: Advantage on initiative & attacks, attackers have Disadvantage. Cannot be targeted by effects.
Paralyzed: Incapacitated. Speed 0. Fail STR and DEX saves. Attackers have Advantage, and crit if within 5ft.
Petrified: Weight x10 and stop aging. Unconscious. Resistant to all damage. Immune to poison.
Poisoned: Disadvantage on attacks and ability checks.
Prone: Can only crawl. Disadvantage on attacks. Attackers have Advantage within 5ft, else have Disadvantage. Spend half speed to stand.
Restrained: Speed 0. Disadvantage on attacks and DEX saves. Attackers have Advantage.
Stable: 0 HP and Unconscious, but no death saves. Any damage stops being Stable. Ends when HP above 0, or regain 1 HP after 1d4 hours.
Stunned: Incapacitated. Fail STR and DEX saves. Attackers have Advantage.
Unconscious: Incapaciated. Unaware. Speed 0. Drop items and fall prone. Fail STR and DEX saves. Attackers have Advantage, and crit if within 5 ft.
Vulnerable: Take double damage.

Advantage: Roll twice, use better.
Immune: Take no damage.
Resistance: Take half damage.
Cover:
Half: +2 AC / DEX saves.
3/4: +5 AC / DEX saves.
Total: Cannot be directly targeted.

Dying: At 0 HP, fall unconscious. Each turn make d20 death save, on 10+ succeed, else fail. 3 success you stabilize, 3 fails you die. A 1 counts as 2 fails, a 20 you regain 1 HP and consciousness. Taking damage adds a failure, if it's a crit it's 2 failures. If remaining damage equals total HP, you die.
Burning: Take 1d4 fire damage on each turn start. Extinguish by falling prone and spending action.
Exhaustion: Cumulative, die at 6 stacks. -2 to d20 Tests, and -5 Speed, per stack. Long rest removes 1 exhaustion.
Nutrition: You need 1 gallon water and 1 pound food each day to avoid exhaustion.
Suffocation: Hold breath 1 minute per Con mod (min 1), then gain 1 exhaustion each turn.
Fall: Take 1d6 bludgeoning per 10 ft (max 20d6). Fall prone when taking damage. Falling into liquid = Reaction DC 15 Athletics or Acrobatics for half damage.
Inspiration: Spend to reroll any dice after rolling it.
Long Rest: Full 8 hour rest. Regain HP, hit dice, ability scores, and class resources. Reduce exhaustion by 1.
Move Through: You can move through an ally's space, or an enemy's space if you're 2+ sizes different than them, or they're incapacitated. All are Difficult Terrain.
Opportunity Attack: When creature within reach moves away, use Reaction to make a melee attack.
Passive Check: Ability check without roll. Equal to 10 + Ability mod + Proficiency.
Proficient: Add your Proficiency Bonus to any rolls for this skill/weapon/save/tool/etc.
Short Rest: An hour of rest. Can spend Hit Dice to recover HP.
Two Weapon: Two light weapons, Bonus Action to use offhand weapon. No positive ability mod to damage.