The revised 2024 edition of the D&D 5E Player’s Handbook includes a Rules Glossary at the back of the book. This glossary is integral to the organization of the rulebook, as described in a sidebar on page 7:

RULES GLOSSARY

If you read a rules term in this book and want to know its definition, consult the rules glossary, which is appendix C. This chapter provides an overview of how to play D&D and focuses on the big picture. Many places in this chapter reference that glossary.

So, for example, the rules will mention that a spell can have a Cone area of effect, but what this means will never be explained in the text: It will only be defined in the “Cone [Area of Effect]” section of the Rules Glossary.

There is also, of course, an Index where you can look up various topics. This is, thankfully, MUCH improved over the 2014 version of the Index, which suffered from a multitude of sins. (The most frustrating, in my experience, was that you’d look something up in the Index and it would tell you to go look at a different Index entry. And sometimes when you looked up that entry, it would tell you to go look at another entry. And then, when you finally followed the daisy chain to its end, there would only be a single page reference which could have just as easily been included at every single entry along the daisy chain! This is completely absent from the 2024 Index.)

Splitting the rules for a game into an explanatory text and a “definitive” rules glossary isn’t a new technique. It’s a format that’s been used by a number of board games over the last couple decades. (For example, Fantasy Flight Games was a big fan of this for a while, and even D&D 3^rd Edition published a separate Rules Compendium that used a similar approach in an effort to “simplify” and “clarify” the rules with a “definitive” reference.)

And, to be blunt, my experience with these glossary-based rulebooks, as I’ll call them, has pretty consistently sucked. They have a pretty easy fail-state in which the rules glossary ISN’T actually authoritative, so you end up with rules split up across multiple locations, which means that

• you’re forced to flip back and forth between different pages trying to piece together the full set of rules you actually need; and
• even when the glossary IS authoritative, there’s no way that you can be sure that’s true, so you end up flipping back and forth anyway.

This fail-state is generally made worse because you need to play Guess What We Named This Entry, which can be capricious at best. Furthermore, these failures seem to be endemic because, in my experience, game rules are inherently procedural (if A, then B, then C), whereas a glossary is organized by topic.

Note: None of this applies to a rulebook which simply includes a Glossary. A normal glossary can be a useful resource for quickly understanding key terminology, and can be even more useful if it includes page references pointing you to the full and primary discussion of the topic. You could remove such a glossary and the game would still be complete.

A glossary-based rulebook, on the other hand, has rules which are ONLY found in the Rules Glossary. This glossary is not merely a reference tool; it’s integral to the presentation of the game. Removing this glossary would change the game.

With all that being said, I tried to go into the 2024 Player’s Handbook with an open mind. At first glance, in fact, it seemed that the Rules Glossary would be a useful reference tool (although it was immediately obvious that its utility would be greatly enhanced if it had page references).

After using it for a little bit, unfortunately, I’m forced to conclude that…

IT SUCKS

To demonstrate, let’s consider a spell’s Range and Target.

“Range” is not, as far as I can tell, covered in the Rules Glossary. (I can’t be 100% sure of this because sometimes you have to guess how the term is being alphabetized — i.e., “Range” vs. “Spell Range”. But the Index doesn’t have a Rules Glossary page reference for it, so I’m fairly confident.) This means that all of the rules for a spell’s Range are located on page 236 in Chapter 7: Spells.

That’s simple enough.

What about a spell’s Target?

Well, that does have a Rules Glossary entry, on page 376, which is:

TARGET

A target is the creature or object targeted by an attack roll, forced to make a saving throw by an effect, or selected to receive the effects of a spell or another phenomenon.

Great! At first glance, we’ve found the rules for Targets!

… except, of course, I have a certain degree of system mastery, and I know this cannot, in fact, be the totality of the Target rules.

Okay, so let’s hit up the Index:

target, 376

Huh. Only one page reference and it’s pointing to the Rules Glossary entry. Maybe the 2024 revision massively streamlined the Target rules and those are the only rules for targets.

Let’s double-check by looking up “spells” and “spell target” in the Index and see if there’s anything there.

Nope.

The reality is that the Index, although much improved, has actually failed here. The rules for a spell’s Target are located on page 237-8. These rules are fairly bulky and, at first glance, seem complete.

But wait, there’s more!

In the Target section, for example, there are rules for areas of effect:

Areas of Effect. Some spells, such as Thunderwave, cover an area called an area of effect, which is defined in the rules glossary. The area determines what the spell targets. The description of a spell specifies whether it has an area of effect, which is typically one of these shapes: Cone, Cube, Cylinder, Emanation, Line, or Sphere.

Okay, so then we go to the Area of Effect entry in the Rules Glossary. This includes essential rules about the area’s point of origin, how to determine if certain parts of the area of effect are blocked, etc. and then it cross-references Rules Glossary entries for each individual shape. (So you might then flip to Cube to figure out the specific rules for how a Cube area of effect works.)

But what if you were coming to this from a different direction? For example, let’s say you were looking at the Thunderwave spell, where it says:

Each creature in a 15-foot Cube originating from you makes a Constitution saving throw.

You don’t know what that means, but “Cube” is capitalized, which indicates a term that’s located in the Rules Glossary. Here you get the specific rules about Cubes which, at first glance, seem complete… but don’t actually include the stuff about how certain parts of the area might be blocked. This is probably okay-ish, though, because even though “area of effect” isn’t capitalized, the entry is titled “Cube [Area of Effect]” and the square brackets indicate that there’s another glossary entry. Yes, you now have multiple pages open and are cross-referencing them to figure out how the rules work, but at least you were able to find everything by following the breadcrumb trail!

But let’s go back to the rules for Targets on page 238 and look at this section of the rules:

A Clear Path to the Target. To target something with a spell, a caster must have a clear path to it, so it can’t be behind Total Cover.

Well, that seems complete and, unlike the “Areas of Effect” section of the same rules, there’s no reference to an entry in the Rules Glossary, so we must be good to go!

… except I know that in the 2014 version of the rulebook, this section reads:

A CLEAR PATH TO THE TARGET

To target something, you must have a clear path to it, so it can’t be behind total cover.

If you place an area of effect at a point you can’t see and an obstruction, such as a wall, is between you and that point, the point of origin comes into being on the near side of that obstruction.

Hmm. What happened to that whole second paragraph?

Well, once again, maybe they removed it from the rules. It did, after all, give rise to the endless debates about whether or not you could target someone standing behind a window. (And, if so, what would happen.)

But by this point I’ve gotten suspicious, and so I go digging a bit and discover that this part of the rule can, in fact, be found hidden in the Rules Glossary! (Although, obviously, not in the entry about Targets!)

Finally, all of this is made much, much worse because Wizards of the Coast is allergic to page references, and so even when they do tell you where you can find more rules, this takes the form of, “See also chapter 1,” and you’re left flipping through a thirty-page chapter trying to figure out what where you’re supposed to look.

CONCLUSION

On the one hand, you can argue that all of the rules are, in fact, in the rulebook, and can eventually be found if you just look in the right place. So what’s the problem?

On the other hand, I want you to think about how many times during this relatively simple rules look up:

• You could falsely conclude that you had all the relevant rules and, therefore, never go looking for the rules hidden away in a different part of the book.
• You needed to have multiple pages open at the same time in order to have all the relevant rules for a single topic. (Then add to this, for example, the spell listing that prompted you to go looking for these rules in the first place.)
• You’re re-reading the same text in multiple places because each entry is partially redundant.

But, also, once you’ve lost trust that either the Rules Glossary or the main text can be trusted to give you a full set of rules, how much time do you waste fruitlessly double-checking to make sure you’re not missing something that’s been hidden from you? (Remember how in one case the partial rules were in the Rules Glossary and the full rules were in the main text, but in the other case the opposite was true?)

Think about the impact all of that has in the middle of a session.

Ignore the broken Index entry and assume we successfully navigated our way through the blind turns: We nevertheless went to page 376, then page 237, then page 364, and then page 361. (And then probably back and forth between them.)

Meanwhile in the 2014 Player’s Handbook, all of these rules were located in a single place on page 204. Look it up and you’re done.

As I mentioned, the 2014 Player’s Handbook is not without its own flaws and shortcomings. My point here isn’t that perfection hasn’t been achieved. My point is that glossary-based rulebooks are systemically flawed, and the 2024 Player’s Handbook is just one example of a fundamental problem, which means that the impact on you and your game will also be systemic and pervasive, affecting it in every part.