The Real is a category of serious, survival-oriented cognitive behavior, a construction of biological nervous systems. The fact that we experience the world as real, concrete, independent and external is a symptom of our sensitive dependence as organisms on an environment.
The organism is a closed system. Its dependency on an environment puts it in the position of a formal system with regard to a system more inclusive than it, because changes of rules or structure within the adaptive system (which by definition survives by changing itself) cannot be derived from nor entailed by anything within the system itself.  As a dissipative system the organism is driven by an external energy source; as a biological system it is part of and dependent upon an ecology external to it; and as an "interpreted" formal system modifications to itself must originate externally. Meaning for the organism lies outside itself. This is where the sense of reality ultimately comes from.
The world is real just to the degree that it determines experience. Were we disembodied minds, not bound to the laws of organic life and the physical universe, we would be free to create experience in any arbitrary way-- and not only free to follow whim, but obliged to, since the game of physical existence provides the rationale for meaningful activity and experience. Even dreams are rooted in reality, their images drawn from waking experience, their messages speaking to us of our life in the real world. Without a real world to respond to, the mind would have to create an imaginary one in which to move-- as in situations of sensory deprivation.
On the other hand, the human organism is not as straightforwardly tied to the Reality Principle as simpler creatures appear to be. We have the remarkable ability to see our own determinism, and thus transcend it, often leading to a more objective relationship to the world. In the same freedom, we create imaginary or ideal worlds as we please, along side the natural one, laying claim to the right to make gratuitous choices. It is in this sense that pleasure opposes itself to reality, rather than in the terms proposed by Freud:
"Just as the pleasure-ego can do nothing but wish, work for a yield of pleasure, and avoid unpleasure, so the reality-ego need do nothing but strive for what is useful and guard itself against damage".
Freud confuses the gratuity of imagination-- wishing-- with the search for pleasure, which he then opposes to the survival value of the useful. But pleasurableness has an ambivalent nature. On the one hand it is a quality attaching to objects or events; on the other, a cognitive judgment concerning them made by the organism with reference to their utility toward survival. The apparent opposition between a pleasure principle and a reality principle, which plays such a large role in Freud's thinking, disappears if we grant that both pleasing/unpleasing and useful/unuseful are survival-oriented discriminations, albeit on differing levels of mental organization. To say that we seek pleasure is to say no more than that we seek what eons of experience in the world have proven beneficial. The organism does not primarily seek pleasure but well-being. Pleasure is the built-in awareness of what is good for it (or perhaps, more precisely, good for the species). The subjectified notion of pleasure as an experience has come to seem like a kind of thing in its own right, rather than a state of well-being originating in the environment. The concept of pleasure, as distinguished from well-being, is an artifact of subjective consciousness. Of course, rats (which presumably do not have subjective consciousness) may seem to seek pleasure itself in stimulation, rather than some good which appears (to a human observer) objectively beneficial. This appearance, however, exists in the eye of the beholder, while the animal has simply judged the stimulus good, though perhaps in error.
The pursuit of pleasure, in Freud's scheme, is actually an expression of the Reality Principle, the pursuit of survival. Let us therefore understand something different by the notion of a pleasure principle. We could refer to it accordingly as the Impulse to Gratuitous Play, or something similarly awkward. Furthermore, a reality principle implies more than utilitarian preoccupations and goal-orientedness, but comprises the whole outward-leaning bent of the mind. In one light, this is the mind's tendency to project its own cognitive processes as an independent external world. In another, it is the search for objectivity and truth. Accordingly, we could call this broadly inclusive principle the Impulse to Reality, of which the many forms of realism and reification are instances. Or, in the interest of preserving a simplicity of language, we could continue to refer to them as the Reality Principle and the Pleasure Principle, but with a clearer understanding.
Apart from pure interest in truth-- which is disinterest-- the concern for the Real is a concern for the future, the spatially and temporally distant, the non-actual. Experience of the real world is largely a construction of visual space and the objects that occupy it. Cognitively, the mind imposes upon the chaos of sensory input various anticipations of patterns of input it has learned it might encounter. One never worries over the actual, but rather over the imagined. Paradoxically, the whole purpose of the Real is to provide a controlling bulwark against non-actual contingencies. One is therefore caught between two modes: accepting the actual and monitoring the potential. The first implies engagement in the here and now, absence of struggle, delight in the shadow of annihilation. The other implies goal-orientedness, fear and anxiety, disappointment and displeasure lurking behind the promise of mastery and survival. The quest for mastery is never guaranteed, and has a way of generating further problems. On the other hand, well-being is not assured simply by abdicating concern. The ego lives between a rock and a hard place, unable to achieve security yet bound by its mandate to try.