I think every table has at least the occasional player who doesn’t read or doesn’t quite grasp what’s written in the rulebooks. I’ve occasionally been that player.

I think it’s worth it to talk to them specifically about the issue but don’t be a hard-ass about it, this is all supposed to be for fun after all. Don’t just suggest “read the book” because to some people that’s basically just saying “here, read this text book” suggest the specifics parts the need to brush up on.

Maybe suggest they make, or just make one for them, a cheat sheet with the necessary info on it that they keep forgetting, depending on what they need it could just be some notes scrawled in the margins or on the back of his character sheet, or maybe a separate print-out or some flash cards.

In my experience my players are excited about the rules and how their characters work - but not all of them learn well from “just reading the rules”, like it literally does not stick. Just telling them to read the rules isn’t going to do anything but make them feel shitty about the game.

Talk to your players about how to help them remember or have easy access to these rules. Make sure you don’t get too accusatory, you do want to play with these people after all.

When I was maybe 8 or 9, my dad offered to teach me to play D&D.

I told him I wanted to be a wizard, so he told me I had to memorize every 1st level spell in the AD&D 2e PHB before he’d let me make a wizard.

I had them down cold in a week.

If your players really want to play, and you want them to improve, talk about it with them. Don’t nag, just set the standard that they need to know how everything on their character sheet works. If they can’t do that, their character can’t remember how to use the feat/skill/spell/item in question at the moment.

Of course, if there are exotic interactions between effects, that’s on the GM to resolve. Likewise you should make some exceptions for edge cases, but spell slots? Come on.

I don’t know if you’re talking in the long campaign, same players context, but I often find that for one shots around half of players, at best, skim the rulebook of the particular system. Myself sometimes I do, sometimes I don’t find time. Some people, like it or not, come to a session mainly to chill and even let the others do most of the adventuring. Others engage with the adventure but don’t feel like engaging with the rules beyond what the GM requires.

I’m also assuming the GM will explain the rules, and I think they are the ultimate authority. So stuff from the rulebook may not even be relevant (thrown out, replaced), and GM is the interface for the rules. I would call it OSR mentality, though some may call it glorified player laziness. But as a GM it may give you more room for your ideas actually.

I think the situation is a problem if players don’t know the rules and get mad when their plans are impossible. I suppose this can happen more often with rules-heavy systems.

Anyway, I think keeping the rulebooks close to the players (either as putting them on the table or sharing PDFs) is good advice.

People can have trouble with the rules because they can’t afford the PHB, or don’t want to shell out for it until they know they actually like to play, or just don’t feel comfortable looking things up in the middle of the session. Sometimes the rules just don’t make sense to someone until they’ve seen how those rules apply during gameplay. I was extremely embarrassed the first few times I had to say “this rule doesn’t make sense to me, can you give me an example?” but sometimes it just takes the right kind of explanation to make it click.

Assuming you have tried different ways of explaining and are pretty sure it’s a memory thing, you could suggest that if a player doesn’t have the PHB, they should not play classes that rely heavily on game mechanics. You could also try giving the confused players copies of just the pages that you think they need, and making it clear that you don’t care if they look things up during a session, provided you actually don’t care. If you really need a group to be good on rules without looking anything up, it might be a situation where you have to figure out how to tell a player to find a different group.

Of it’s a general issue with the players forgetting rule, talk to them about switching systems. I wouldn’t play Pathfinder 1e for example with a very casual or rp focused group. There are so many systems that do exactly what we want on different levels of crunch. If you need recommendations you can ask in this group, but talk to your players. This works especially when your players don’t care about the system you play.

Other than that, there are a ton of cheat sheets for how mechanics work online, to print out.

Hope I could kinda help

When I bring in a new board game I also teach it to the group. I fully expect that as a DM it is similarly a part of my responsibilities to coach the players about these rules. After all I want to play this with them.

At some point though, I indeed expect my players to have the initiative to look some things up for themselves. But the D&D PHB is 320 friggin pages. That’s not a casual “give it a quick read before our next session” kind of thing.

But I think it also depends on your schedule. We occasionally had a month or more between sessions and it’s quite natural to forget some aspects of a game (any game really) when you’ve been off for that long.

I’ve played with two groups, and everyone has figured out how to handle their class features.

I think it’s worth a chat with the players.

Depends on the casualness of the group.

Pick-up games, almost nobody knows the rules. Don’t use complex games with them, use tiny little indie games instead. Get an OSR game like Knave, and it’s almost impossible to not understand the game.

Longer-term groups, I do expect everyone to read the rules, and using more complex games is fine. Someone who won’t, and especially if they picked a more complex class or skills, needs to read the book, change characters, or go to another group.

It depends on several things.

First, how do you treat your game nights? Do you treat them as a casual social gathering where it’s ok to show up fashionably late; or to not show up without warning; or to drop out last minute because of whatever non-emergency reason? If so, don’t be surprised players also treat it as something casual and social, and reading rules isn’t casual or social. Maybe D&D just is too complex and not the right game for your table if you just want to run a casual social event.

Personally I treat my D&D style campaign game nights similar to how I’d treat coaching a sports club. If you want to be a striker on a soccer team, and you don’t understand the off-side rules and don’t want to learn them, no coach in their right mind wil put you on the field either. Sure I give my players time to learn, and don’t expect them to know everything from day 1, but the absolute minimum I expect is a willingness to improve.

Practically, what I do for each player in my campaign is to compile a document which I expect them to focus on. They roll up a fighter, I will include the fighter class entry plus common special maneuver. They roll up a wizard, I will include the wizard class entry plus their spell book. They roll up a merchant (which I consider the most complicated class in my game and will discourage inexperienced players from taking it), I will give them the class entry plus a 101 intro to the economics of my campaign world. They have 3 months (approximate 10-15 weekly sessions) to understand the material I’ve given them, before I start reconsidering their presence in my campaign. Obviously there’s some flexibility, it’s not a life or death matter; but again I do expect at least some sign of willingness.

Next, please do understand I did specify campaign game nights above. Obviously things are different with one-shots like convention games or open table games at the local game store. I don’t expect the players to know any rules there and will happily guide them by the hand from start to finish.

For a quick one-shot to test out the system, most of my players will just skim the rules, and that’ll be enough. But if I run a long-term campaign I expect my players to have a basic grasp of the rules, but most importantly know how their characters rules works.

I will happily explain and help players get started. But if they ask me for 100th time which die to roll; don’t know how their character works; or similar basic things, I will get pissed at some point and ask them to please learn the game we’re playing.

You don’t need to know every single rule, but a basic grasp of them is just the bare minimum or I will kick them out of the game at some point. This hasn’t happened to me yet, all my players are very good at picking up new systems.

I let the rule-book on the PC side of the table, and expect that player get at least a basic understanding of the rules, especially if they have special power (Like spells/psy/cyberware).

That said, if players struggle to understand the rules, may-be it’s also an issue with the game

I wouldn’t require players to read the whole rulebook or books. However I expect players to know the basic rules that come up all the time after a while. Also I expect players to know what their spells and abilities do and have the page numbers noted on their character sheet/pdf/whatever next to the ability for easy referencing. This is something I make very clear during session zero. There is some learning by doing and there is some reading up you need to do.

In return players can expect me to know all the rules which I expect to be relevant during a session (e.g. if there will likely be underwater combat I’ll make sure I refresh my knowledge on that). As a GM I will make sure I know the spells and abilities of all enemies and monsters I use and how they might interact with the PCs. I’ll also have page numbers for rules, spells and monsters ready if things get unclear.