What makes something real?
There is a room, within dwells a relentless Dragon, I am warned not to go in but I do so anyway. If the warning was false and the beast is not real, I'll remain in the room, unaffected. However, if the warning was true and the beast is real, I'll be devoured, thus affected…
Something real has the ability to affect.
Reality is comparative, it only makes sense when at least two objects are considered, one affecting another. "Is the Sun real [to me]?"
Reality is reciprocal, two objects can affect each other, an object can affect itself. "Am I real to the Sun? To myself?"
Reality is not an absolute value, it is a spectrum, one object can deeply affect another, not at all, or anything in between, when both objects are equally capable of affecting each other, they both share the same degree of reality. "How much does the Sun affect me? How much do I affect the Sun?"