Is it alright to play dumb on a job interview?

Employers are not looking for dumb employees, so I would not advise playing dumb. You can show that you are intelligent without coming across as a "know it all." I think that your friend gave you some bad advice because that would keep you from getting the job.

I guess if you don't really want the job, you should play dumb. There is a fine line between being confident and being cocky and overbearing. All of the supervisors I have ever worked for wanted someone who is confident in their skills and that they can do the job but also realize there is training involved. I would never play dumb or advise someone to play dumb in a job interview.

Well I wouldnt necessarily advice playing dumb:P But I have heard of alot of employers passing over qualified employees because they are TOO qualified. I have no experience in the interviewing process, because I am a teenager and have had one interview in my life. But in my opinion i think an employeer would like someone with someone with knowledge but willing to learn oppose to someone to qualified or someone who pretends that they dont know anything

I don't know if I would advice that or not but I wouldn't act like I knew everything. I've had an interview and just acted normal and not try to act too smart or too dumb. It worked out ok but that was years ago when my area was hiring but I didn't land the job. Kind of a bummer but what can you do except find something else to do work wise.