Using Card Sleeves on your Summoner Wars cards is a very good idea for a number of reasons:

- You push your cards around the play field throughout the game, causing potential wear on unprotected cards over extended play.

- Your opponent will handle some of your cards in a game of Summoner Wars. Though it is common politeness to clean your hands before playing a game that is going to have you handling other people's stuff, human skin produces oil naturally and a plastic protector keeps your cards from absorbing those oils.

- When 2 Players both want to play the same faction it is easier to separate out whose cards are whose at the end of the game when the decks are both sleeved with differing sleeves.

- When playing a 4 player game, if teammates are both playing the same faction, it is easier to keep track of whose cards are whose throughout the game.

The good news is that there are an abundance of card sleeves out there that are a perfect fit for Summoner Wars. The card sleeves you want to look for when shopping for Summoner Wars sleeves are Japanese-sized card sleeves, or more maybe more commonly known as card sleeves designed to fit YuGiOh cards.

If anyone knows of any good online sources for these sleeve sizes that offers good prices and service, please feel free to share. I found several places after a quick Google search, but haven't had any interaction with these places in order to recommend them. Your local game store might also be a good place to find these sleeves.