Random lasers do not necessarily require strong microscopic scattering. A suitably designed multi-mode laser cavity can act as a nonresonant system if it supports a manifold of spectrally overlapping modes. This manifold must have equal mode losses and strong mixing. We will discuss various cavity configurations within this category. Particularly interesting is the geometrically-unstable cavity, which has chaotic ray characteristics. The mode patterns of this cavity are self-similar and are characterized by a fractal dimension (Nature 402, 138 (1999)).