How 5th Edition Dungeons and Dragons Works

Introduction

This post is for people who are new to 5th Edition Dungeons and Dragons - particularly those who have played earlier editions. The 5th edition of the game has a number of differences from earlier versions, and my intention is to give an overview of how the game works.

This is not intended for people without any knowledge of roleplaying games in general. I will not be defining basic concepts - a certain amount of knowledge will be assumed. It is assumed that the reader knows the "d" convention for naming polyhedral dice, is familiar with the six Abilities (Str, Dex, Con, Int, Wis, Cha), and has a basic knowledge of how Race and Class are used in the game.

This article does not go into full detail, and is not intended to replace the Player's Handbook. There are a bunch of rules that apply to specific situations that I will not go into here. Specific rules always override general rules.

Roll d20

Most rolls in the game are made with a single d20. All of these will be either an Ability Check, a Saving Throw, or an Attack Roll. In fact, Saving Throws and Attack Rolls are just special kinds of Ability Checks, but we separate them because there are spells and abilities that can affect them differently. For example, a spell may affect Saving Throws and Attack Rolls, but this does not mean that they affect Ability Checks. Or it could affect Ability Checks only, and not Saving Throws or Attack Rolls.

When making a roll, you will add certain modifiers. You will almost always add an Ability Modifier, and you may also be able to add your Proficiency Bonus.

Ability Check

Your six Abilities will range from 3-20. Your Modifier depends on what the Ability score is, and it is the Modifier that you will use the most.

The DM will tell you when you need to roll an Ability Check. If, for example, you are trying to bash open a stuck door, your DM will ask you to roll a Strength check. You will roll a d20 and add your Strength modifier to the roll. If instead you are trying to pick a lock, you will roll a Dexterity check. If you are searching for traps, roll an Intelligence check.

The DM will set a Difficulty Class (DC) that you need to roll over in order to succeed - the harder the task, the higher the DC. High rolls are always better.

Proficiencies

You will have a certain number of Proficiencies as a result of your Class and Background. These are the areas in which you may add your Proficiency Bonus, which starts at +2 and slowly increases as you go up levels. Proficiency is always all-or-nothing. Either you have Proficiency in something or you do not. You can have Proficiency in Skills, Tools, Vehicles, Musical Instruments, etc.

For example, if you are searching for traps, and you have Proficiency in the Investigate Skill, your DM will allow you to add your Proficiency bonus to the Intelligence check. If you are trying to pick a lock and you have Proficiency with Thieves' Tools, then you can add your Proficiency bonus to the Dex check.

Each Skill or Tool is correlated with one Ability. Investigate checks are always Intelligence. Perception is always Wisdom. Athletics is always Strength. To get the highest bonuses, match your Skill Proficiencies with your high Abilities.

Saving Throws

A Saving Throw is a special kind of Ability Check. Your Class gives you Proficiency in two Saving Throws. One will always be Dex, Con or Wis - which correlate to 3rd Edition's Reflex, Fortitude and Will saves - and the other will be Str, Int or Cha. Most saving throws will be of the first three, but there are spells and abilities which will force you to make one of the other kinds of save.

There are usually no other modifiers to Saving Throws - just your Ability Modifier and your Proficiency Bonus if your class gives you Proficiency in that save.

Death Saves

There is a special kind of Saving Throw called a Death Save. When your hit points are reduced to 0, you will make a Death Save on each of your turns. Death Saves are usually unmodified d20 rolls. If you roll a 10 or better, you succeed. If you roll a 9 or lower, you fail. Notice that there is a slightly better chance of succeeding than of failing.

If you roll three failures before you roll three successes, you die. Your soul leaves your body and starts making its way through the Astral Plane to its final resting place. You can of course be raised or resurrected under certain circumstances, but otherwise you are dead. If you roll three successes before you roll three failures, then you are stable with 0 hit points and you are safe - you no longer need to roll Death Saves.

If you roll a 1 on any Death Save, that counts as two failures. If you roll a 20 on any Death Save, then you are immediately revived with 1 hit point and can move and take an action as normal.

Magical healing automatically stabilises an unconscious character. Another character can stabilise an unconscious character by using a Healer's Kit or by making a Wisdom (Medicine) check.

Attack Rolls

An Attack Roll is another kind of Ability check. If you are attacking with a Melee Weapon, it is a Strength check. If you are attacking with a Missile Weapon, it is a Dexterity check. If you are attacking with a spell, it may be an Intelligence, Wisdom or Charisma check, depending on your class (see Spellcasting below).

If you are attacking with a Melee Weapon that has the Finesse property, you can choose whether to make a Str or Dex check. Usually you will make this determination at character creation and stick with it - you will be either a Str user or a Dex user. Dex users will focus on missile weapons and Finesse weapons such as rapiers, which Str users generally will wear heavier armour and use high-damage weapons.

If you are throwing a weapon that has the Thrown property, then you make the same kind of check that you would if you were using that weapon as a Melee Weapon.

You also get to add your Proficiency Bonus if you are Proficient with the weapon that you are using. Your class determines what Weapon Proficiencies you start with. For example, Fighters start with Proficiency in all Martial and Simple weapons (which is all of them), whereas Clerics start with only Simple weapons, and Sorcerers start with only daggers, darts, slings, quarterstaffs and light crossbows. You can use weapons that you are not proficient in, but you do not get to add your Proficiency Bonus.

Advantage and Disadvantage

Here's the fun part. If there is a circumstance that helps you with any one of these d20 rolls, the DM can give you Advantage. If there is a circumstance that hinders you, the DM can give you Disadvantage.

If you have Advantage, you will roll 2d20 and take the highest. If you have Disadvantage, you will roll 2d20 and take the lowest.

There are occasionally simple modifiers to d20 rolls, but this mechanic is used for all other circumstantial effects. If you think you should have Advantage on a roll, ask your DM.

How Combat Works

To start combat, the DM will determine whether any parties are Surprised. This is usually a Wisdom (Perception) check. Characters and creatures that are Surprised cannot do anything on the first round of combat.

Initiative is a straightforward Dexterity check, usually with no additional modifiers. Combat proceeds by descending in the initiative order.

On your turn you can do two things: move up to your Movement Speed, and take an Action. Sometimes you can also take a Bonus Action. These do not have to be done in any particular order, and you can split your move however you like, as long as you do not exceed your Movement Speed in a turn.

Actions, Bonus Actions, Reactions

An Action can be one of ten different things: Attack, Cast a Spell, Dash, Disengage, Dodge, Help, Hide, Ready, Search or Use an Object. These are the only Actions you can take on your turn. Full details on how each of them work can be found on p. 192-3 of the Player's Handbook.

Some abilities will give you a Bonus Action. You do not get a Bonus Action unless an ability or spell tells you that you do, and you can never have more than one on your turn.

You also always have a Reaction, but you will not always need to use it. The most common use of a Reaction is to make an Opportunity Attack against an enemy that is leaving your Reach - there are no other circumstances that trigger Opportunity Attacks. A Reaction takes place on someone else's turn, and you can never have more than one before you take your next turn.

You cannot "hold" your action until later in the initiative order. However, you can take the Ready Action. To do this, you specify what the Action will be and what will trigger it, and then you use your Reaction to do that thing when the trigger occurs. For example, when the goblin comes around the corner, use the Attack Action to fire a crossbow at it. Remember that you can have only one Reaction before your next turn.

Attacking

When you take the Attack Action, you make an Attack Roll with a weapon. You do not have to have this weapon already in hand before doing this - drawing a weapon is not itself an Action. If you exceed your target's Armour Class (AC), then you have scored a hit.

There are a lot of things that can modify the Attack action, especially for combat-heavy classes like Fighters, Paladins and Barbarians. For example: at 5th level, Fighters can make two Attack Rolls when they use the Attack Action.

Casting a spell is never an Attack action. It is always the Cast A Spell action, even though there are spells that let you make an Attack Roll (see Spellcasting below).

Damage

The weapon (or spell) you are using will tell you what Damage to roll. You will add the same Ability Modifier to the damage roll that you used for your Attack roll. If you added your Str modifier to the Attack Roll, you also add your Str modifier to the Damage roll.

Wearing Armour

Your Armour Class is 10 plus your Dexterity modifier. You may wear Armour to raise this.

Your Class may give you Proficiency in Light, Medium, or Heavy Armour, and/or with Shields. Light Armour always allows you to add your full Dex modifier to your AC. Medium Armour allows you to add up to two points of Dex modifier to your AC, while Heavy Armour does not allow you to add your Dex modifier at all. Some types of Armour also impose Disadvantage on Dexterity (Stealth) checks. Each type of Armour sets what the base AC is when you wear it. For example, if you are wearing Scale Mail, which is Medium Armour, then your AC is 14 plus up to two points of Dex modifier.

If you wear Armour that you do not have Proficiency with, you have Disadvantage on Ability Checks, Saving Throws and Attack Rolls based on Str or Dex, and you can't cast spells. It is best to only wear Armour that you have Proficiency with. Also, certain types of Heavy Armour have a minimum Str requirement, and if you do not meet that requirement, your Movement Speed is reduced.

Using a Shield adds +2 to your AC regardless of the type of shield.

Two-Weapon Fighting

If you take the Attack Action and make an Attack Roll with a weapon that has the Light property, you can use your Bonus Action to make another Attack Roll with another weapon that has the Light property that you hold in your other hand. You do not add your Ability Modifier to the Damage Roll for the second attack. There are ways to make two-weapon fighting better, but any character can do this. Remember that you can have at most one Bonus Action per turn.

Critical Hits

When you roll a Natural 20 on any Attack Roll, you have scored a Critical Hit. Roll the weapon's Damage dice twice before adding your ability modifier. Critical Hits with big weapons are better than Critical Hits with small weapons. There is no such thing as a "critical miss" or a "fumble".

Wounds and Healing

You cannot go below 0 hit points. When you drop to 0 hit points, you are Unconscious and have to start making Death Saves on your turn.

You can never be healed to higher than your Hit Point Maximum. There are spells and effects that can give you Temporary Hit Points, but these have a limited duration. Any damage you take must be removed from your Temporary Hit Points first.

You can regain Hit Points by magic, or by Resting. There are two types of Rest. When you take a Short Rest - one hour - you may spend your Hit Dice to regain Hit Points. You have one Hit Die per level of a type determined by your Class. For example, a 5th level Cleric has 5d8. You can roll as many Hit Dice as you like during a Short Rest and add that to your Hit Point Total. Each Hit Dice you roll reduces the number you have available for later Rests.

When you take a Long Rest - eight hours - then you regain all of your Hit Points and half your level's worth of Hit Dice. Most spellcasters also regain spell slots on a Long Rest.

Conditions

Certain effects and circumstances can apply Conditions on a character, which last until they are cancelled. For example, when you are reduced to 0 Hit Points, you are Unconscious. There is a specific set of rules that cover each Condition, and some Conditions themselves impose other Conditions. For example, when you are Unconscious, you are also Incapacitated.

Special Attacks

You can use an Attack action to Grapple or Shove. To Grapple, you roll a Strength (Athletics) check, and your opponent rolls either Strength (Athletics) or Dexterity (Acrobatics). If you succeed, then your opponent is Grappled. Note that this means only that their Movement Speed is reduced to 0 - being Grappled does not impose any other condition. Shoving a creature works in a similar way, but you force them to move away from you.

Spellcasting

This is the area that perhaps has changed the most from earlier editions. The idea of memorising and forgetting spells is no longer used.

A spellcaster will need to determine three things up front: Spellcasting Ability, Spell Attack Modifier, and Spell Save DC.

Their Spellcasting Ability is determined by their Class. A Wizard's Spellcasting Ability, for example, is Intelligence. A Cleric's is Wisdom. A Bard's is Charisma.

Your Spell Attack Modifier is your Spellcasting Ability Modifier plus your Proficiency Bonus. Your Spell Save DC is that plus eight.

When you cast a spell against a nonwilling target, the spell will tell you whether you have to make an Attack Roll, or whether the target has to make a Saving Throw. In the former case, you will roll your Spell Attack Modifier against your target's AC. In the latter, you don't need to roll any dice - your target is forced to make a Saving Throw to beat your Spell Save DC.

Preparing Spells

Preparing spells works differently for different Classes.

Most Classes know a certain number of spells at each level. For example, a 3rd Level Bard knows 6 spells. Clerics, Druids, Paladins and Wizards work slightly differently. Wizards have a Spellbook, which contains all the spells that they have available, and then they Prepare a certain number of those spells. They cannot Prepare spells that are not in their Spellbook. Clerics, Druids and Paladins can Prepare any spells off their spell list, but again, only a limited number. Clerics, Druids, Paladins and Wizards can change which spells they have Prepared when they complete a Long Rest. Check the rules for your Class when you create your character.

You never have to Prepare more than one "copy" of a spell. Once you have a spell Prepared, you can cast it as many times as you have Spell Slots.

Casting Spells

To cast a spell in combat, you must take the Cast a Spell action. Some spells can be cast as a Bonus Action, or as a Reaction.

You can usually cast only one spell in your turn. However, if that spell uses a Bonus Action to cast, you can use your Action to cast a second spell, so long as it is a Cantrip. You can not cast levelled spells on the same turn that you use your Bonus Action to cast a spell.

Some spells specify that they can be cast as a Reaction. These are cast on another creature's turn and do not affect what spells you can cast on your own turn. For example, if a creature in their action pushes you off a cliff, you can use your Reaction to cast Feather Fall.

You can cast a spell while wearing armour, if you are Proficient in that armour.

Spell Slots

When you cast a spell, you must spend a Spell Slot of that spell's level or higher. So a 3rd level spell can only be cast using a Spell Slot of 3rd level or higher. You cannot use a low-level spell slot to cast a higher level spell, but you can always use a high-level spell slot to cast a lower level spell, and in fact some spells gain in power when you do so.

For example, Magic Missile is a 1st level spell that creates three magical darts that automatically hit for 1d4+1 damage each. It requires a 1st level Spell Slot to cast. If you use a 2nd level Spell Slot to cast it, you get four darts. If you use a 3rd level Spell Slot, you get five darts, and so on. Many spells can be "overpowered" in this way.

Most Classes regain all their Spell Slots when they take a Long Rest. Warlocks regain all their Spell Slots on a Short Rest. Wizards have an ability that allows them to regain a few Spell Slots on a Short Rest, and then all of them on a Long Rest.

Concentration

Some spells are Concentration spells. They usually have a long duration, but you can have only one of them active at a time - you cannot cast two Concentration spells and have them both active. The second one automatically dispels the first. If you take damage while a Concentration spell is active, you must make a Constitution Saving Throw in order to keep it active, otherwise it is dispelled.

Cantrips

Cantrips are special spells that are part of a spellcaster's background knowledge. They do not require Spell Slots to cast, and can be cast at any time, whenever you like. Some of them get better as you go up levels.

This means that a dedicated spellcaster need never actually use a weapon if they have a damaging Cantrip available, such as Fire Bolt or Eldritch Blast. Usually you pick your Cantrips when you create your character, and you can occasionally get more as you go up levels. It is a good idea for Wizards and Sorcerers to take some damaging Cantrips for when they run out of Spell Slots.