I started coding up an Android version of my favorite 2-player card game, Schotten-Totten. I got as far as asking the game's inventor what he'd charge me for rights to release it free and open source.
Unfortunately, they'd already given exclusive license to another electronic publisher. This made me sad but it's their Intellectual Property and so I stopped. To this day there isn't a multiplayer Schotten-Totten game for Android at any price.
Today I found that another programmer didn't ask permission first, and now he's subject to a lawsuit.
Yikes! I feel like I dodged a bullet.