Nonspherical polymer particles are emerging in various applications, such as optics and drug delivery, where their geometry can modulate packing, flow, light transport, and biological fate. Nevertheless, industrial production of polymeric particles remains limited to spherical ones because most synthesis routes towards non-spherical particles are capital-intensive, laborious, or difficult to scale. This dissertation addresses the bottleneck using condensed droplet polymerization (CDP), a solvent-free, vapor-phase, surface process that forms polymer domes/discs in minutes by condensing monomer on a cooled substrate and initiating free-radical polymerization in the droplets. This thesis establishes the fundamental principles of CDP: (i) condensation dynamics sets the droplet size distribution; (ii) polymerization time and initiator supply control conversion and hence dome size/density in ways consistent with free radical polymerization kinetics; and (iii) low substrate surface energy is required for discrete, circular domes. Building on these principles, this thesis provides application-level validations of CDP-synthesized substrate-attached domes: coatings that tune optical transmittance and reduce glare, and, uniquely, the detachment of domes to obtain free particles. Collectively, these results position CDP as a scalable synthesis platform that delivers controllable particle parameters with functional performance.