If you spend any time around tabletop RPG tables or forums, you will quickly run into a handful of shorthand terms: RAW, RAI, homebrew, and the Rule of Cool. They all describe the same basic tension. A roleplaying game is a set of printed rules, but it is also a story that real people are making up together. How closely should you stick to the book, and when should you ignore it for the sake of a great moment?
This glossary walks through each term using Dungeons & Dragons 5th Edition as the default reference, since it is the most common starting point. The ideas, though, apply to almost any system you play.
RAW means "Rules as Written": playing exactly what the printed rulebook says, word for word, with no interpretation or house adjustments. If the text says a spell affects creatures within 20 feet, RAW means 20 feet, full stop.
Playing RAW has real strengths:
The limits show up at the edges. Rulebooks cannot anticipate every situation, and strict RAW can occasionally produce results that feel silly or contradict common sense. Some rules are simply ambiguous, and a few are widely agreed to be mistakes. RAW is a great default, but it is not a substitute for judgment.
RAI stands for "Rules as Intended": what the designers were clearly trying to accomplish, even if the wording came out clumsy. When the literal text produces a strange result, asking "what was this rule meant to do?" often lands you somewhere more sensible than the letter of it.
Close to this idea is a phrase from the OSR (Old-School Renaissance) corner of the hobby: "rulings, not rules." The idea is that a GM should not need a paragraph for every situation. When something unexpected happens, the GM simply makes a fair, reasonable call in the moment and play continues. A good ruling is quick, consistent with how similar situations were handled before, and respectful of what the players were trying to do.
RAI and rulings are how tables fill the gaps that no rulebook can fully cover.
Homebrew is custom content: anything you create or change yourself rather than using straight from an official book. It is one of the oldest and most beloved traditions in the hobby.
Homebrew covers a wide range, including:
Homebrew exists precisely because no published game fits every group perfectly. Maybe the official rules for a certain situation feel clunky to you, or your setting needs a creature that does not exist in any book. Building it yourself is part of the fun, and for many GMs it is the most creative part of the job.
The Rule of Cool is an informal, table-level principle: allow an awesome, cinematic action even when the rules do not strictly support it, simply because it is fun and makes a great story.
Picture a player who wants to leap off a collapsing bridge, grab a chandelier, and swing across a chasm to tackle the villain. The strict rules might make this a chain of difficult, easy-to-fail checks. The Rule of Cool says: this is exactly the kind of heroic beat the game exists to create, so lean toward letting it happen, perhaps with a single dramatic roll.
It is not a written rule in any rulebook. It is a mindset that reminds everyone the goal is a memorable night, not a flawless rules simulation.
These approaches are not enemies. Most tables blend all of them, and the blend works best with a little care.
The healthiest tables treat the rules as a shared agreement, not a private toy. Coolness that comes at someone else's expense is a poor trade.
There is no single right answer, and a lot of it comes down to experience and taste.
New GMs are often well served by starting close to RAW. Running the game as written lets you learn how the system actually behaves before you start changing it, so your later tweaks come from understanding rather than guesswork. It also gives you a stable baseline to compare against.
Experienced tables, on the other hand, tend to tune the game to their preferences. Once you know a system well, you can see which rules serve your group and which get in the way, and homebrew becomes a precise tool rather than a shot in the dark. Many long-running campaigns are quietly full of small house rules that nobody at the table would give up.
A reasonable path: learn the rules, then bend the ones that need bending.
Wherever your table lands on the spectrum from strict RAW to enthusiastic homebrew, the right answer is the one that makes your game more fun for everyone in the room. Mini Kraken's custom systems and character sheets are built with homebrew in mind, so the rules can flex to fit the story you actually want to tell.