Building Versus Modifying

Many times, a small adjustment to an existing creature, item, adventure, or other part of the game can serve you just as well as building something brand new. Before you delve into creating your own new content, ask yourself a few questions. First, does something similar already exist?

When answering this question, look beyond the surface level.

Maybe you want a 5th-level clawed centipede creature that can make Attacks of Opportunity and that regenerates unless hit by acid or fire damage. It might not look very much like a troll on the surface, but the statistics for a troll are going to get you most or all the way there. Ask yourself what you’ll need to change between your idea and the existing material. This will help you decide between using the original rule with minimal modification, using the original with adjustments, starting with the original as a framework to build your own, or just starting from scratch. Finally, ask yourself how much time you have to prepare the content, what overall impact you expect it to have in your campaign, and how important any discrepancies from existing material are to the core concept. The less important an element is to your game, or the less time you’ll be using it at the table, the more likely you should modify something that already exists.