DFT studies (B3LYP/6-31G*) on mono- and dichloro derivatives of benzene, naphthalene, B2H122-, four-atom-sharing condensed systems B20H16, and monocarborane isomers of B20H16 are used to compare the variation of relative stability and aromaticity between condensed aromatics. The trends in the variation of the relative energies and aromaticity in these two- and three-dimensional systems are similar. Aromaticity, estimated by NICS values, does not change considerably with condensation or substitution. The minor variation in the relative energies of the isomers of chloro derivatives is explained by the topological charge stabilization rule of Gimarc. The compatibility of the cap and ring orbitals decides the relative stability of CB19H16+.