Single crystals of CsCdCl3, CsCdBr3, CsMgBr3, and MgBr2 doped with 0.1/5% Ni2+ were grown by the Bridgman technique and studied by variable-temperature optical absorption and luminescence spectroscopies. At cryogenic temperatures all these systems are dual emitters; i.e., they emit light from two distinct, thermally nonequilibrated excited states. The emitting higher excited state is T-1(2g) in Ni2+:CsCdCl3 and Ni2+:CsCdBr3 and (1)A(1g) in Ni2+:CSMgBr3 and Ni2+:MgBr2. This crossover manifests itself in a change from red broad-band to yellow sharp-line luminescence, and it is rationalized on the basis of crystal field theory. Temperature-dependent luminescence as well as two-color pump and probe experiments reveal that in Ni2+:CsMgBr3 and Ni2+:MgBr2 the T-1(2g) state lies only about 70 and 170 cm(-1), respectively, above (1)A(1g). The effect of crystal field strength on thermally activated nonradiative multiphonon relaxation processes in the bromides is examined for both (1)A(1g)/T-1(2g) higher excited state and T-3(2g) first excited-state emission. Two-color excited-state excitation experiments are used to monitor Ni2+ excited-state absorption transitions originating from T-3(2g).