The Basic card type is one that's been around since the inception of the game. Until now, it's only been on five cards. We all know that when you make your deck, you can put in any number of basic lands; this has been the rule that we have all gone by since we learned to play. A lot of design is questioning the tenets set before us. Why are we only allowed to have 4 of each card in a specific deck? The answer is more complicated than one might think.
Imagine if you will: A world where there are no restrictions on the amount of each card you can play. In this world, Spike decides he wants a deck with 20 Lightning Bolts, 20 Browbeat, and 20 Mountains. This makes for some very quick games. Also, there are only so many Lightning Bolts and Browbeats in the world. If Spike's deck wins some tournaments, everyone is going to want to try and get 20 Browbeats, driving the price sky high.
I propose a hybrid. I've created a few unique cards that, while not very powerful, can be effective in multiples. These cards have the Basic supertype as well as reminder text to let players know that they can have more than four in a deck. This past week's cards of the day have been showcasing a colorless cycle of Basic sorceries. Here is a cycle of basic creatures to show off a little more of what being Basic can do.
Frontline Spearman is good by itself, but can be brutal against a ground assault in multiples.
Splitting Starfish is a card that is great defensively, and worthwhile to have quite a few in your deck. Be careful, though. They can only hold off an offensive deck for so long.
The flavor for this card is a bit silly, and I like it that way. I've always felt that most goblins just want to be left alone to drink goblin wine or somesuch. This guy wants to share his drink with some schmo on the battlefield, preventing the other guy from actually fighting for a little while. Fun and dangerous in multiples, just like goblins should be.
One of the things I want to stress about basic cards is that the rarity of them shouldn't be higher than common. If you make a basic rare card, it will be problematic; not only because of cost, but for just being able to get enough to build a deck with. These cards should be easily accessible. I feel that they should one per pack, like basic lands. If there are five or six basic cards in a given set, getting enough of them shouldn't be a problem.
I hope that these designs have helped you see a little bit more how the Basic supertype can be implemented in ways that can create decks that have 14 of a specific card instead of the maximum of 4. These cards can be great skill testers for experienced deckbuilders as well as newbies. Figuring out how many is the right amount can bring about much discussion.
Also: If there is anyone in the Fargo area willing to do some playtesting with cards created by myself or others, let me know. I don't have a lot of time to spare for such things, but I think it would be fun.