You won't do reality check in your non-lucid dream on purpose. It will just happen, you will get an urge, your subconscience will do it for you.

But first, you will have a tiny bit of awareness. This you will have from questioning your reality in waking life, just before you RC. The questioning of reality, the "wow, what if this is a dream" will give you this awareness in your regular dream and you will RC spontaneously. By the time you RC, you will already be fully aware and lucid and RC will only confirm what you already know, or partially, and RC will get you there the rest of the way.

So RCs are important. But the awareness question, when you question your reality and you believe that you could be in a dream at that very moment, is even more important. Because that's what gets you lucid.

http://www.dreamviews.com/induction-...hecks-rcs.html