I am DMing for the first time, and I am really excited about playing D&D. I love the idea of it because it is so open ended. I want to increase the amount the players can do in terms of skills, weapon types, armour types, races, etc. Is this okay?
If so, does everyone do this, or do people play entirely with only official assets? Also what about omitting rules entirely? For example, to simplify something to make it more streamlined.
In about 35 years of playing role-playing games, I have seldom witnessed anyone play 100% by-the-book.
A few bits of advice:
Don’t take the names of things too seriously. What really matters is the results of rules, not the names they use.
The “in game” justification for a rule may be different from the “game design” reason. Unfortunately, many games only give you the “in game” justification and leave you to puzzle out the “game design” reason yourself. When the “in game” justification and the “game design” reason seem less connected, it is often an attempt to keep the rules simple enough for tabletop play.
If a rule doesn’t seem to make sense, take a step back. Remember that somebody thought it made sense. At least some of their co-workers thought it made sense. At least some of the playtesters thought it made sense. Etc. Try to figure out why it made sense to those people. Seek out people who like the rule and ask them why. (You might still change it, but it will then be because you want a different rule, not because you misunderstood the rule.)
It is a good idea to give a rule a try before changing or discarding it.
Never be afraid to overrule a rule at the table when the results don’t make sense.
Discuss rule omissions, changes, and overruling with the rest of the group. While the group ought to give the DM the benefit of the doubt when it comes to such things, the DM ought to also consider the input of the players.
As much as possible, make sure players know about rule changes up-front. Players will make decisions and plans based on the rules. If a rule needs to be changed or clarified after play begins, talk to the players and figure out how to make up for a change that invalidates their past choices or future plans.
Never be overly beholden to consistency. If, in retrospect, a rule change didn’t turn out well, change it again. Retcon if you really need to.
(Retcons are often less necessary than you might think. The real world is messy and full of seeming contradictions. Why should the fantasy world be any different?)
Read lots of different games. Read any design notes you can find. The more you understand what rules have been tried and what the intent behind rules are, the better positioned you are to make house rules and on-the-fly rulings.
Accept now that you’re going to make mistakes. That’s OK. We all do.
Of course it's okay. Games are made up by people like you and me; people like you and I are able to change rules just as well.
That doesn't mean it's easy. Chapter 9 in the Dungeon Master's Guide is all about tweaking the game rules with options or your own ideas. It starts with some very good advice about the pitfalls of tackling rules design:
Before you add a new rule to your campaign, ask yourself two questions:
- Will the rule improve the game?
- Will my players like it?
If you're confident that the answer to both questions is yes, then you have nothing to lose by giving it a try.
It continues with more concrete advice for what kinds of changes to the rules are particularly likely to cause problems, and then dives into a variety of ready-made optional rules to get a feel for what tweaking D&D involves. I urge you to read the chapter carefully, and experiment to your and your players' hearts' content. ("Contentedness" for all involved being the most important result of a new rule.)
First congrats to refereeing your first game.
Second in my experience the vast majority of role players kit bash their campaigns. From what I seen the campaigns that go 100% "by the book" are a definite minority. So feel free to whatever you want.
With that being said there are a few piece of advice I give to somebody in your position.
For your first couple of session try to run something that is designed for first time referees. For example the Phandelver adventure out of the starter set. The reason for this is so you get a feel how the system is supposed to be run which give you a better understanding of the game you want to run.
When you say you run x system, players will expect certain things because of that. While is more than Ok to make modification to suit your vision it I courteous that you spell out the changes that will impact them as players. For example I use Swords & Wizardry, a original D&D clone, as a foundation for my Majestic Wilderlands campaigns However I have created a lot of options and additions to reflect how my setting works. The stuff that effects the players I wrote into a supplement. Now you don't need to be that elaborate but do spell out the difference you plan to make.
Also note that for most campaign, new spells, new monsters, new items are expected and don't need to be spelled out beforehand. If you plan to run combat different or the paladin doesn't work like the PHbB says it does then you need to spell out the differences.
Homebrewing D&D is totally okay! But it might not be such a good idea for a first-time DM.
The risk with creating homebrew rules is that you might unbalance the game. For example you might accidentally add a weapon that is way way better than all the existing weapons. The fighter character who can make effective use of that weapon would become very powerful; the cleric and wizard and rogue, who can't use that weapon, would be reduced to basically the fighter's sidekicks. That might not be fun for them.
As another example, you might accidentally create a race that is way better (or way worse) than all the existing races. Anyone who created a character with that race would have a character that was better (or worse) than the other characters, for the entire span of your game.
Usually the way homebrew happens is, people try the vanilla game, see some mechanics they don't like, and make up a rule that fixes it. For example one very common houserule is to change the mechanics for death and dying, so that player characters don't die as easily after dropping to 0 hit points.
Summary: if there's something specific you don't like about the game, feel free to house-rule to fix it. But I'd recommend against creating new content just for the fun of it -- that's very dangerous, especially for someone not used to the system. Try playing with just the base content until you feel confident you know what you're doing.
I would venture to say that (based on no hard evidence, merely personal observation) D&D probably has one of the highest ratios of modified to completely by-the-book campaigns run in the market. Ironically, D&D is also on the rules-heavy side of the spectrum -- one would think that its players prefer following the game's specific rules closely. I personally view D&D as sort of a "rules market;" the core rules and its splatbook supplements are great resources to draw rules from, but only selectively.
However, that selection of rules will end up being different for every group and DM. One of my favorite parts about playing D&D is the amount of material available for it, but you will inevitably come to find that you don't like a very large part of that material. Sometimes you'll see a spell that you think is a great concept, but the way it's executed through the rules is just bizarre or obviously out of place for its spell level, and so you want to place it at a higher one. Other times you will find rules that you think are just plain stupid, and can't help but want to omit them entirely.
D&D has no qualms about you acting on those desires, and like others have pointed out, the DMG even gives some advice on it. The most important rule to keep in mind is Rule Zero: you, the DM, reserve the right to change anything and everything about the game that you're playing. You're effectively the supreme god of your fantasy universe (nobody knows you exist, though).
P.S.: One more thing before you go ham on your homebrew rules: unless you have a very firm grasp on the rules and how they interact, it's best to do just a little research to see if a rule is actually as bad as you think it is before omitting it from your game or changing it. You wouldn't want to accidentally make the game less fun by omitting seemingly-lame rules that actually had a crucial function. You can always change the rules at a later point if you and your players all agree that it sucks, but I think it is a good policy to ask someone else that's played with that rule, or try it yourself before changing it. I typically give a new game system "the old college try" completely by-the-book for a few sessions, then during those sessions players speak up about which rules they don't like (or their inadequacy just becomes apparent to everyone).
When playing with an established group I rarely see a completely unmodified game, however when playing for the first time or in a new group I recommend giving the game a try as written. Until you have a good understanding of how the game plays, it will be hard to make changes that are still balanced.
When making changes (most of this is discussed in the DMG):
Reuse an existing mechanic if at all possible. Change the theme, leave the balance.
Ask yourself "is there a good mechanical reason a player would not use this?"
As yourself "is there any mechanical reason a player would use this?"
Mechanical bonuses should be paired with unavoidable mechanical penalties, RPG penalties should only balance RPG bonuses.
Every player is different: some care very much about the numbers and an imbalance will ruin their game; others only care about the story and don't mind if their character's numbers suck due to your change (again see the DMG). If you have any "numbers" players you should try very hard not to break the balance.
Also, read this Wizards of the Coast article before changing classes: Modifying Classes.
Whether it's 'okay' depends on who you ask, what it is, and why you've made it.
Tweaking the existing rules has been covered by other answers quite comprehensibly, so I'm going to focus using homebrew to expand the available content in the form of a new weapon, armour, races, etc., as asked in the first part of the question.
Who you ask:
Maybe my experience is different to the other answerers here, but I've found some players and spectators to be really quite hostile to homebrew. Most seem to consider homebrewing a grey area at best, and usually unnecessary.
What you make, and how it affects whether it's 'okay':
Homebrewing a weapon is more likely to be considered okay by the community than a spell, race, feat, or class (in that order) - probably because you can have a real-life precedent. For example, noone has a problem with adding a Heavy Flail (1d12 bludgeoning, heavy, two-handed).
How its purpose affects its acceptability
A little anecdote which may be illustrative. When I mentioned on my first visit to a new gaming club that I have over two dozen new classes, there were groans. That's because new classes, are seriously major additions to the 5th edition game, more than a spell or race. However, people are generally more receptive when, instead, I tell them that for each of my four campaign settings I have merely half a dozen new classes each. As part of a setting, suddenly these classes seem to have a purpose.
Here's the specific questions I ask my players, as feedback on for my own homebrew:
Does it step on another option's flavour?
Does it step on another option's mechanic, ability or party role?
Is it worse or better at performing said role?
Does it follow the format and protocol of the existing game?
Let's put these questions into action. I'm going to give quite detailed examples from my own settings, not to advertise myself, but because picking an actual example I've run with players will probably make a better illustration than using general terms.
Is it interesting or flavourful? Does it add something new to the world, or represent a character concept peculiar to this setting?
Let's add the Halfrung Coat, a heavy armour giving AC15, used by royal knights of one particular faction. It's exactly in between ring mail and chain - no mechanical purpose. But why don't the royal knights have chain mail or better? Maybe metal ore or skills are rare... yet the dwarf towns inside this human-led faction are known for their plate armour... much better equipped than the royal knights. Now my mechanically inconsequential addition is indicative of a political situation in my world. Now my creation has a purpose, it's much more likely to be 'okay'.
In my experience, the more distinctive and flavourful a new piece of homebrew is, the more 'okay' it is likely to be, especially if it can be any kind of plot hook. (With work, even homebrew as major as new archetypes and classes can be plot hooks and play a part in story elements.)
Does it step on another option's flavour?
Here we have a point against my Halfrung Coat... Why didn't I just give my royal knights ring mail? Ringmail's whole purpose is simply to be weak and cheap. However, I'm not overwriting Ringmail, I'm giving a middle options. But perhaps it wasn't strictly necessary - making it perhaps not 'okay' any more.
Does it step on another option's mechanic, ability, or party role? Is it worse or better at performing said role?
Let's take a new example. I have a fighting style in one setting named after one famous historical warrior. The style gives +1 to hit when using a versatile weapon in two hands. Our Fighter, if chooses this, is getting accuracy at the expense of damage-dealing. iIs this trampling on another fighting style's schtick? Maybe archery, but not for the melee styles.
If I had a fighting style giving +1 to hit while using a finesse weapon in only one hand, our Fighter would have to decide whether to use that or the duelling style. It's in competition with an existing game element - which is (in my anecdotal experience) - more likely to be rejected, resisted, or complained about by players.
Does it follow the format and protocol of the existing game?
To make one's homebrew 'okay', we need to find a balance between giving it a distinctive mechanical feature (or combination of features) and making it completely foreign.
For example, let's not make a class who, instead of proficiency, begins with disadvantage on their attacks, loses it at mid level and then gains permanent advantage at 17th. It's interesting and flavourful but is completely ditching a staple of the edition, common to all classes.
Summary
Many people don't like homebrew added to the game. But if you give it a unique story or setting purpose, without competing with or overwriting an existing option, then it's more likely to be accepted.
If you want more flexibility than the D&D family offer you perhaps you should try a different system. I've played quite a few systems and I can't think of any that have as many rules and D&D for so little effect. Hence the HUGE pile of mechanics supplements.
I don't think it's easy to get these days but Dragon Warriors has a similar "medieval fantasy" feel, similar character classes, dungeons etc with about 1% of the rules.
Runequest is pretty simple, stats and skills, percentile as I recall and there are many others to choose from. Mechanically I would advise against a system with many die types for task resolution, the enthusiasm for a multitude of dice can make for some very odd effects - Shadowrun is a good example.
As other have said. It's fine to do what you like with a system. Once you've purchased the IP it's yours to do as you want with and house rules are the rule (as it were). Use what works for your group and don't forget it's about having fun. Watch all the player dice rolls and keep yours hidden. Don't be afraid to make up your results to fit with the flow of the game - i.e. if a lucky NPC kills a player with a single hit you can change it :) but don't let off a player if they have a bad roll. They know what they roll and if you're sparing them the consequences of an unlucky roll they are going to lose the tenseness that makes for a fun game.
