When you take the Dash action, you gain extra movement for the current turn. The increase equals your speed, after applying any modifiers. With a speed of 30 feet, for example, you can move up to 60 feet on your turn if you Dash.
Any increase or decrease to your speed changes this additional movement by the same amount. If your speed of 30 feet is reduced to 15 feet, for instance, you can move up to 30 feet this turn if you dash.
If you take the Disengage action, your movement does not provoke opportunity attacks for the rest of the turn.
When you take the Dodge action, you focus entirely on avoiding attacks. Until the start of your next turn, any attack roll made against you has disadvantage if you can see the attacker, and you make Dexterity saving throws with advantage. You lose this benefit if you are incapacitated or if your speed drops to 0.
You can lend your aid to another creature in the completion of a task. When you take the Help action, the creature you aid gains advantage on the next ability check it makes to perform the task you are helping with, provided that it makes the check before the start of your next turn.
Alternatively, you can aid a friendly creature in attacking a creature within 5 feet of you. You feint, distract the target, or in some other way team up to make your ally's attack more effective. If your ally attacks the target before your next turn, the first attack roll is made with advantage.
When you take the Search action, you devote your attention to finding something. Depending on the nature of your search, the DM might have you take a Wisdom (Perception) check or an Intelligence (Investigation) check.
Sometimes you want to get the jump on a foe or wait for a particular circumstance before you act. To do so, you can take the Ready action on your turn, which lets you act using your reaction before the start of your next turn.
First, you decide what perceivable circumstance will trigger your reaction. Then, you choose the action you will take in response to that trigger, or you choose to move up to your speed in response to it. Example: If the goblin steps next to me, I move away.
When the trigger occurs, you can either take your reaction right after the trigger finishes or ignore the trigger. Remember that you can take only one reaction per round.
When you ready a spell, you cast it as normal but hold its energy, which you release with your reaction when the trigger occurs. To be readied, a spell must have a casting time of 1 action, and holding onto the spell's magic requires concentration . If your concentration is broken, the spell dissipates without taking effect.
You have until the start of your next turn to use a readied action.
Pick a target within your attack's range: a creature, an object, or a location.
Make an attack roll: roll a d20 with the appropriate modifiers. The ability modifier used for a melee weapon attack is Strength, and the ability modifier used for a ranged weapon attack is Dexterity. Weapons that have the finesse or thrown property break this rule. Some spells also require an attack roll. The ability modifier used for a spell attack depends on the spellcasting ability of the spellcaster. You add your proficiency bonus to your attack roll when you attack using a weapon with which you have proficiency, as well as when you attack with a spell. If the total of the roll equals or exceeds the target's Armor Class (AC), the attack hits.
If the d20 roll is 20, the attack hits regardless of the target's AC (Critical Hit). If the d20 roll is 1, the attack misses regardless of modifiers or the target's AC.
On a hit, roll to determine damage. When attacking with a weapon, you add your ability modifier to the damage. A spell tells you which dice to roll and whether to add any
modifiers. On a Critical Hit, you get to roll extra dice for the attack's damage against the target.