Page 6 - DnD 5e - Xanathar's Guide to Everything

THE C O RE RULES ADVANTAGE AND DISADVA NTAGE
Even if more than one factor gives you advantage or
This book relies on the rules in the three core rule-
disadvantage on a roll, you have it only once, a nd if you
books. The game especia lly ma kes frequent use of
have advantage and disadva ntage on the same roll, they
the rules in chapters 7- 10 of the Player's Handbook:
cancel each other.
"Using Ability S cores," "Adventuring," "Combat," a nd
"Spellcasting." That book's appendix A is also crucial; C OMBINI NG D I FFERE NT EFFECTS
it contains definitions of conditions, like invisible and Different game effects can affect a ta rget at the same
prone. You don't need to know the rules by heart, but it's time. For example, two different benefits can give you
helpfuJ to know where to find them when you need them. a bonus to your Armor Class. But when two or more
If you're a DM, you should a lso know where to look effects have the same proper name, only one of them
things up in the Dungeon Master's Guide, especially the (the most powerful one if their bene fits a ren't identical)
rules on how magic items work (see chapter 7 of that applies while the durations of the effects overlap. For ex-
book). The introduction of the Monster Manual is your ample, if bless is cast on you when you're still under the
guide on how to use a monster's stat block. e ffect of an earlier bless, you gain the benefit of only one
casting. S imila rly, if you're in the radius of more than
THE DM ADJUDICATES THE RULES one Aura of P rotection, you benefit only from the one
One ruJe overrides all others: the DM is the final author- that grants the highest bonus.
ity on bow the rules work in play.
Rules a re part of what makes D&D a game , rather R EACTION TIMING
tha n just improvised storytelling. The ga me's rules are Certa in ga me features let you take a s pecial action,
meant to help organize, a nd even ins pire, the action of a called a reaction, in response to some event. Making
opportunity attacks and casting the shield s pell are two
D&D campaign. The rules a re a tool, a nd we want our
typical uses of reactions. If you're unsure when a reac-
tools to be as effective as possible. No matter how good
those tools might be, they need a group of players to tion occurs in relation to its trigger, here's the rule: the
bring them to life a nd a DM to guide their use. reaction happens after its trigger completes, unless the
description of the reaction explicitly says otherwise.
The DM is key. Ma ny unexpected events can occur in
a D&D campaign, a nd no set of rules could reasonably Once you take a reaction, you can't ta ke a nother one
account for every contingency. If the rules tried to do so, until the sta rt of your next turn.
the game would become a slog. An alte rnative would be
RESISTANCE AND VULN ERABILITY
for the rules to severely lim it what characters can do,
Here's the order that you apply m odifiers to damage: (1)
which would be contrary to the open-endedness of D&D.
a ny relevant damage immunity, (2) any addition or sub-
Here's the path the ga me ta kes: it lays a fou ndation of
traction to the damage, (3) one relevant damage resis-
rules that a DM can build on, a nd it embraces the DM's
tance, and (4) one relevant damage vulnerability.
role as the bridge between the things the rules address
Even if multiple sources give you resista nce to a type
and the things they don't.
of damage you're taking, you can apply resistance to it
only once. The same is true of vulnerability.
TEN R ULES T O REMEMBER
A few rules in the core rulebooks sometimes trip up a PROFICIENCY BONUS
new player or DM. Here are ten of those rules. Keep- If your proficiency bonus a pplies to a roll, you can add
ing them in mind will help you interpret the options in the bonus only once to the roll, even if multiple things in
this book. the game say your bonus applies. Moreover, if more than
one thing tells you to double or halve your bonus, you
EXCEPTIONS SUPERSEDE GENERAL RULES double it only once or halve it only once before apply-
General rules govern each part of the game. For exam- ing it. Whether multiplied, divided, or left at its normal
ple, the combat rules tell you that melee weapon attacks value, the bonus can be used only once per roll.
use Strength a nd ra nged weapon attacks use Dexterity. (
That's a general rule, and a genera l rule is in effect as BONUS ACTIQN SPELLS
long as something in the game doesn't explicitly say If you wa nt to cast a spell that has a casting time of 1
otherwise. bonus action, remember that you can't cast any other
The game also includes ele me nts- class features, s pells before or a fter it on the same turn, except for can-
s pells, magic items, monster abilities, and the like- that trips with a casting time of 1 action.
sometimes contradict a gene ral rule. When a n exception
and a general rule disagree, the exception wins . For ex- CONCENTRATION
ample, if a feature says you can make melee weapon at- As soon as you start casting a s pell or using a s pecial
tacks using your Charisma, you can do so, even though ability that requires concentration, your concentration
that statement disagrees with the general rule. on another effect ends instantly.
ROUND DOWN 'TEMPORARY H IT POI NTS
Whe never you divide or multiply a number in the game, Temporary hit points aren't cumulative. If you have tem-
round down if you end up with a fraction, even if the porary hit points a nd receive more of them, you don't ~:
fraction is one-half or greater. add them together, unless a gam e feature says you can.
Instead, you decide which temporary hit points to keep.