We introduce a currently hot topic in probability theory, the theory of scaling limits for massless random fields of gradients in all dimensions. The random fields are a class of model systems arising in the studies of random interfaces, random geometry, Euclidean field theory, the theory of regularity structures, and elasticity theory. We outline the ideas in physics behind scaling limits and motivate renormalisation group theory. After explaining how non-convex energy term can influence the scaling limit, we outline our result on scaling limit to the continuum Gaussian Free Field in dimension d=2,3 for a class of non-convex interaction energies. In particular, we aim to show that the Hessian of the free energy governs the continuum Gaussian Free Field. The second result concern the Gaussian decay of correlations. All our results hold in the regime of low temperature, and moderate boundary tilts.