Let's take for example Farmville social game. Many clones have appeared and they have very similar concept, most of them have in the same way Neighbor, tools, etc. So legally, where is the edge of how much concept can be copied. Or is just like that the concept can not be legally protected but only a design? It would be logically that this could be protected. But how, what can be protected here? Also in web portal you could say that others are not allowed to copy the same registration process for example, but every x portal has it the same. So legally, how much concept can be copied?
This is a really interesting question, for example, who has the copyright for chess, poker, blackjack etc. Can I go ahead and make a game similar to Farmville and call it FarmTown?
Well, there is a lot of racing cars and companies still making more. Why you can't do another one? Maybe you can do it but not have the license to show cars brands. You know what I'm trying to say? You may copy the concept but you may not show the same images, names, cars, etcetera.
Ah, so then i guess its a question of how you make use of their trademark and whether or not you are infringing any if their brands / partners. Providing you do not infringe their trademark / associated trademarks, then copying the concept should be ok. But i would consult with someone who has a digital legal background before starting anything.