Quick question: Is it alright if I use art from other games as placeholder and/or to show my design ideas on forums (not serious commercial presentations or pitching), and give full credits to the where the art came from?

E.g. "Hey guys, I designing an interface for my RTS game. The placeholder is from Starcraft. Please comment!" Then proceed to show a modified Starcraft interface to illustrate the ideas.

Would it be considered unethical?

Yes. And expect that Cease and Desist letter in your inbox.

Yeah, while I'd be fine with seeing an interface or game design element explained in this way, be assured that there are potentially rights holders who would not.

This is probably okay when explaining in an email or IM client to a friend, but it would be better knocking up some simple art of your own or asking an artist friend to do a little bit if you want to post it publicly.

I find it odd that anyone would need comments on their interface if it was using placeholder anyway. Wait until you have elements of your own before you show it off, otherwise it only means that the original design team did a good job, and you know how to copy paste. What's the point of that?

I think its ok for things that are not trivial to create yourself (3D models, sounds, skymaps?), but for example textures and such shouldnt be too hard to make yourself. I think if you use placeholders, their only purpose would be to make the game functional in temporary lack of original content. So you dont need to get great looking polished textures to show off that you have implemented a moving player. You can just draw a stick man in paint. That way people can see that you are showing off the functionality, not the content.

There are sites like OpenGameContent to grab placeholders with CC licenses.

Interfaces can be easily mocked up in photoshop. Use the square tool, and then type some text in them.

Thanks for the input. ^__^