I was just looking through the App Store when I saw two blatant Blokus clones. One named Exsqueezeme and the other named Kibosh. I am quite sure that neither of these individuals had the permission of the original creator of the game. How does that work yet iBeer sued iPint and Scrabble sued its clone? These games are not even slightly modified. They are exactly the same but named differently. They even mention Blokus in their app descriptions. Can someone clear this up for me?

IANAL but:

Anyone can sue anyone, regardless of whether they're in the right. For most individuals and small companies, being sued by a large company is enough to get them to agree to the demands being made, whether or not the opponent has a case. The cost of a legal battle means you have to be really sure of yourself to willingly enter one.

So why have Blokus not gone after the clones? Maybe they don't think they'd win (Scrabble has a lot more copyrightable material - Blokus just has a grid and some polyominoes) or maybe they don't consider the mobile market much use to them.

Either way, I'd *love* to see an official Blokus app on the iPhone.

You can't copyright or trademark gameplay. Clones are legal as long as they use different artwork/sounds and a different name. That's how most Tetris clones get into trouble (they use names like Blocktris) and how that Scrabble clone got into trouble (Scrabulous is too close to Scrabble). A similar name on a similar product is trademark infringement.

That doesn't stop people from suing clones though. Usually the clone maker would win any suit, but it would take time and lots of money. Discretion is usually the better part of valor in those cases.

(disclaimer:IANAL) I think you might be able to *patent* gameplay (which is a PITA from what I've heard, and also can be costly to get the patent), but Bachus is right, you can't *copyright* gameplay, so in most cases you can clone away! Some content, like artwork, audio and verbiage (e.g. story) are copyrightable though, so be careful.

Also, if you use wording that is even close to the claimed owners' trademark(s)/trade dress you will eventually be sent a terse legal letter explaining that you have to immediately stop selling your product, or else blah, blah, blah... I don't think it'd be wise to publicly give details, but it happened to me with a product I worked on. We didn't even know there was a possible infringement in the first place, but the company who claimed ownership of the trademark/trade dress demanded the wording be removed and some paperwork signed to agree not to use their claimed trademark/trade dress. We complied and it didn't cost us a thing, and the dispute was resolved without issue (and we didn't have to change the gameplay). I'm not suggesting all such matters would typically be resolved in such a simple fashion, but I added this here as an example of something that *did* happen, for reference. Trademark holders do have a legal responsibility to defend their trademark(s)/trade dress or risk losing claim to it.