*"5E" is short hand for 5th edition. The published name of the game is just Dungeons and Dragons, but the press and fans call the last few editions 3.5, 4E, and 5E. This is useful when looking up rules explanations on Google.
The action economy in 5e is actually pretty streamlined compared to the previous two editions, but it's still complex to explain to someone who has never done this before. When you tell people they can't do something because of the rules, it slows stuff down and it feels against the spirit of what the game is about. As a game master, I want to encourage people to do things intuitively and err on the side of having fun.
The interesting part is that we started playing before the rules were published, and the playtest rules for 5E encouraged "the rule of cool" over a strict system. The issue of course is that we eventually found a few ways to "cheat" the rules. Later on when the game launched, the RAW (rules as written) for 5E indicates that most if not all of these minor cheats were addressed by specific rules, or allowed as actions if you purchased a Feat. However, they are scattered about the PHB (Player's Handbook). I'm going to try to collate the basics here and examples of the "cheats", because this gives you an idea of how to carry forward the mentality when playing the game and wondering if there's something you can or can't do.
In the end, always ask, as a DM I might let you get away with it because it's a cool idea.
Rounds/Turns
A
Round is a 6 second bracket of time in which all characters (allies and foes) can take a set of actions. When you do something, that's your
Turn.
Free Actions
You can take one
free action on your turn. You can do it at any point as part of your
Move or
Action. Taking more than one free action is possible, but then game says you should use your Action. Examples of a free action.
- Draw one weapon
- Fish out a potion bottle
- Drink a beer (but not a potion*)
- Drop to the ground
- Hand something to another player
- Pick up something from the ground.
You can drop any item in your hand or talk for free, these aren't counted against your Free Action, and I generally let people talk longer than 6 seconds.
Action/Move
On your turn, you can choose to
Move up your movement speed and take an
Action. You are free break up your move, taking your Action in the middle of the the move.
Examples of an Action:
- Cast a Spell
- Use your Attack Action (note, some classes get more than one attack as their action)
- Drink a Potion/Use a Magic Item
- Disengage (if you move away from a foe, they get a free attack on you, unless you do this)
- Use a Skill Check*
- Ready an Action*
- Improvise!
*Note that Skill Checks are generally an action, but I allow for the difference between a passive Skill check (like remembering that trolls don't like fire) versus an active one (trying to convince the troll not to attack you). Performing an Athletic action can generally be rolled into the Move action, this allows you do to cool things like swing from chandeliers without wasting an attack.
Bonus Actions:
Bonus actions are taken on your turn and you can mix them up with your
move and
action as well. They are usually
constrained to a feature of a class, spell or feat. The big exception is that anyone can attack with a weapon in your off hand as your bonus action. This is a way to get a second attack in without relying on a class feature.
Some example of bonus actions.
- Bardic Inspiration is a bonus action
- The Wizard Spell "Misty Step" can be cast as a bonus action
- The Cleric Spell "Spiritual Weapon" can be cast as a bonus action
- The Rogue Ability "Cunning Action" is a bonus action (and lets you do a bunch of things that are usually constrained to Actions)
- The Fighter ability "Second Wind" is a bonus action
- A Druid of the Moon can Wild Shape as a bonus action (but not any other druid)
Reactions
Every character has one potential
reaction to spend a round. Reactions can happen anytime during the turn, in response to something else happening (usually to you!). Like bonus actions, they are
usually constrained to a feature of a class, spell, feat. There are two big exceptions:
Attack of Opportunity: If you're engaged with a foe and they move 5' away from you, you can
spend your reaction to attack them as they run away.
Readied Actions: As an
action, you set up a trigger condition. (I'll run over and attack the first person who comes through the door in the north wall). If that trigger condition happens, you interrupt the ongoing action and take your full action right then. This doesn't reset your initiative count. If the trigger doesn't happen, you don't spend your reaction.
Reactions reset at the start of your characters turn, not at the start of round.
Other examples of a Reaction
- The Fighter "Protection" ability lets you use your shield to interfere with an attack on an ally
- The Wizard apell "Shield" creates a +5 AC bonus in response to a hit
- The Bardic ability "Cutting Words" lets you roll your inspiration die to minus out an attack
- The Rogue ability "Uncanny Dodge" lets you half the damage in response to a hit you can see
- The Feat "Defensive Duelist" is like the spell "Shield" but you use your proficiency bonus for the AC boost
Errata
Stuff implied or specifically covered by the weird bits in the rules
Armor requires a "donning or doffing" (There is actually a fucking chart for this called Donning and Doffing Armor, pg. 146 PHB) and takes a not insignificant amount of time to do so. The relevant bit is that Shields take an action to "Don" or "Doff" so switching out from Shield and melee to a two handed ranged weapon, or shield to two handed weapon, is a significant.
This fucks with casters that don't use holy symbols. If you are a shield/weapon spell caster, (bard, eldritch knight, druid) you have a problem, since you need a component pouch or a spell focus to cast most of your spells. This means you'd get stuck putting away your sword and then drawing out a holy symbol in the same turn, as an action. We were straight ignoring this until we saw the War Caster Feat, which specifically calls out this constraint by giving you the ability to ignore it. So keep that in mind (or start your turn with your main hand free and draw a weapon only when needed).
If you fight with two weapons, you can't draw both weapons in a turn for free. There's actually a Feat called Dual Weapon fighting that lets you draw both weapons at once.
Drinking a potion takes an action, which puts it in direct contradiction to the "drink a beer" free action. But it's consistent with "use an item".
Taking things out of a Bag of Holding takes an action. (which makes sense)
That's all I've got, I think I covered most of the crazy, let me know if you have feedback.