We present a generalized extension of the detailed kinetic and experimental analysis for studying rapid gas phase chemical chain reactions initiated by short pulse laser photolysis. The key ingredients of the technique are pulsed laser initiation of the chain by dissociation of a small fraction of a precursor molecule to produce radicals (Cl2→hνCl⋅+Cl⋅), followed by time resolved, infrared chemiluminescence detection of product HCl(v) emission from the propagation steps (Cl⋅+RH→k1 R⋅+HCl(v), R⋅+Cl2→k2Cl⋅+RCl). This laser initiated chain reaction technique is now extended to encompass a far wider range of chain kinetic rates, mechanisms, and product state distributions. Three prototypical systems are investigated which demonstrate distinctly different facets of the extended technique: (1) Cl2/HBr—a slow chain reaction system, (2) Cl2/CH3SH—a multiple chain reaction system, and (3) Cl2/H2—a slow starting chain reaction system in which the product emission appears after an intital induction period. Quantitative rate data are obtained for several chain propagation steps: Br⋅+Cl2→Cl⋅+BrCl, k = 2.4(±0.2)×10−15 cm3 molecule−1 s−1; Cl⋅+CH3SH→⋅CH2SH+HCl(v), k = 4.3(±1)×10−12 cm3 molecule−1 s−1; ⋅CH2SH+Cl2→Cl⋅+ClCH2SH, k = 2.6(±1)×10−13 cm3 molecule−1 s−1. The results illuminate a more general approach to precise kinetic and mechanistic studies of complex chain reactions under nearly ideal psuedo-first-order laboratory conditions.