The Excalibur team has built a number of games over the years. During our last few game jams, we started paper prototyping soon after our brainstorming process. It’s been working great and we highly recommend giving it a try!
More flexibility
Changing rules or mechanics that only exist on paper is a lot faster than having to adjust any code you may have written for those changes. It’s possible to alter your game without much worry, because you’re operating primarily in the realm of imagination, rather than within the constraints of your software development environment.
Paper prototyping can also help avoid the “sunk-cost fallacy”, which encourages you to stick with whatever you’ve spent a lot of time on just because you’ve spent a lot of time on it. Instead, you can change as much or as little as you wish without having to worry about deleting a bunch of code that you’ve already written.
Identify problems early
You also have the opportunity to fix game design problems before you've devoted time to implementing them in the actual software. While we were paper prototyping Sweep Stacks, we uncovered a game design complication with how the board filled up over time. Without having to write any code, we were able to determine a solution for the issue and implement it directly when we started programming the game.
Easier once you start writing code
If you’ve spent time prototyping, you'll have a more concrete idea of what you want your game to be. When you actually start writing code, you can begin with a more specific idea of what you want to accomplish. We’ve found it’s much easier to visualize and architect our code when we have a clear idea of how the rules and systems of a game will work together.
Virtual paper
While it's called “paper prototyping”, this process doesn't literally have to be done with paper, or any physical components at all. Virtual paper prototyping can be just as effective, and allows you to collaborate more easily with remote teammates. There are plenty of wireframing and “virtual tabletop” web apps out there that you can use to put together a digital prototype for your game (we usually use Excalidraw).
Give paper prototyping a try
The next time you’re working on a game, try doing some prototyping before you write any code. Adjust your rules, modify your designs, and dream of what you want to build.