Whether you have a broken a wrist or you want to mess with your friends by dishing out crazy combos, this DIY project uses an Arduino and an old video game controller to create customisable combo buttons you can set to do almost anything. You'll need a game controller you're comfortable disassembling, an Arduino, and some basic supplies you may already have if you're getting started with DIY electronics.
When you're all finished, you'll have your finished game controller and an activation button (a number of accessibility-friendly switches are sugested) that will fire up the programmable actions. The video above actually does a great job of walking you through the whole project from start to finish. You can check out more photos of each step -- along with the full walkthrough and the code required to make it all work -- at the link below.
Granted, with the broken wrist example, you'd have to have this done in advance, but DIY Hacks and How Tos, who made the video for Make, notes that it's great for people who are disabled, have limited mobility, or in combination with other accessories, such as headset buttons and foot pedals. To make it work best for someone with limited mobility, you'll have to tweak the code and the activation button to work with the person's range of motion. It's a bit of work, but it's a straightforward hack that can help that friend in physical therapy play games with you.