One of the things I like most about 5th Edition D&D is its simplicity. While it is still significantly more complex than systems like Powered by the Apocalypse or FATE, it took many of the complex ideas from past editions of the game and streamlined them. 5th Edition isn’t perfect, but it is my preferred system for most campaigns. Still, there are things that 5th Edition just doesn’t do with its core rules, so improvisation and rulemaking are important for anyone wanting to run more advanced games of D&D. Making supplementary rules for your games can be very rewarding, but it can also ruin your games if you don’t know what you are doing. Here are some tips for creating your own mechanics and systems for 5th Edition D&D.
Keep it Simple. 5th Edition is a relatively simple system, so unless you have no other option, keep your homebrew rules simple as well. This will help make the rules easy to explain and easy to follow. While it may be tempting to make your mechanics granular and have modifiers for every little thing that could affect it, you should stick to only having modifiers for significant factors and have the minor effects roleplay-only.
Keep it Consistent. This goes hand-in-hand with keeping it simple. If your rules work the same way every time, then it will be easy for your players to remember and it won’t cause unnecessary confusion during your game. If you decide to change the way your mechanic works (perhaps you playtested it and realize something doesn’t work the way you intended it to), make sure to let your players know so that they won’t be confused or feel cheated by a sudden change in the rules.
Look at Other Games. I know a lot of people reading this exclusively play D&D, and perhaps even only 5E. That’s fine, not everyone enjoys every kind of game, and while I’d recommend branching out and trying new games, do what’s best for you and your group. However, even if you don’t intend on playing other games, it is helpful to look at other systems that do what you’re trying to do. Other games often have mechanics for whatever you’re wanting to do, and those mechanics could serve as a baseline for your homebrew, even if they have to be altered dramatically to fit 5E.
Remember what is Practical. It can be tempting to lift rules from video games. However, keep in mind that video games often use significantly more numbers than tabletop games because the consoles can calculate the results of the numbers instantly while you would be stuck calculating the numbers yourself if you use a similar system. This can drag games down if you have to deal with too many numbers, so if you do take an idea from a video game, make sure that the math is easy to handle.
Conclusion. Making a system to fit your campaign can be challenging, and there’s no specific formula for crafting the perfect homebrew rules. Learn to be patient and always think things through before you implement them, and remember to always keep your rules simple, consistent, and practical. If you follow these guidelines, I can’t guarantee that the mechanics you make will always work or be great, but they will help you in the creation process and lead to less headache and more success.