Anyone can join the group. Join requests will be automatically approved.
In most gallery folders, sketches will be accepted, if there is a good description of the displayed thing. The description can be included in the image or in the image comments. The focus is on the idea, not primarily the execution of the art.
This particularly applies to the "materials" folder, where you can submit designs for future materials. These materials require a somewhat believable description of the material. It doesn't have to be hard science, but it should be something that a person can accept as a well-thought concept.
Submissions with a dominance of weapons, war machines and fight scenes will not be accepted. This groups has a focus on the peaceful side of future.
The limit should be set to 5 deviations per week, and deviations will be reviewed. If the limit doesn't work as expected, please drop me a note and I'll look into it again. Also, please be patient if it takes a while to review a submission, at times I'm visiting dA only infrequently.