Yu-Gi-Oh is, like Pokemon and others, a fairly popular collectible card game where players battle using a deck of cards and a specific set of rules. Also like its companions, Yu-Gi-Oh has inspired a number of spin-off Minecraft ideas, like resource packs and full-on mods which bring their inspirations to life in new and interesting ways. YuCraft is similar, though it does stand out in a few ways.
YuCraft is a server where players can do card battles, much like the game which inspired it. However, unlike packs or mods, it requires no downloads at all! Just hop on (currently version 1.8), set up your deck, and dive into battle! It even has a fully fleshed out city where players can duel in proper arenas! Participate in your own duels, or just spectate others as they go head-to-head. If you're familiar with Yu-Gi-Oh at all, the rules will feel familiar. Neat!
Remember, you can check out all of these servers and many more right here on the Minecraft Forum Server List! There are tons of servers to check out, and more are added every day. Enjoy!