Experiments on flammability limits, ignition energies, and flame speeds were carried out in a 11.25-and a 400-liter combustion vessel at initial pressures and temperatures of 100 kPa and 295 K, respectively. Flammability maps of hydrogen-nitrous oxide-nitrogen, methane-nitrous oxide-nitrogen, ammonia-nitrous oxide-nitrogen, and ammonia-nitrous oxide-air, as well as lean flammability limits of various hydrogenmethane-ammonia-nitrous oxide-oxygen-nitrogen mixtures were determined. Ignition energy bounds of methane-nitrous oxide, ammonia-nitrous oxide, and ammonia-nitrous oxide-nitrogen mixtures have been determined and the influence of small amounts of oxygen on the flammability of methane-nitrous oxide-nitrogen mixtures has been investigated. Flame speeds have been measured and laminar burning velocities have been determined for ammonia-air-nitrous oxide and various hydrogen-methane-ammonianitrous oxide-oxygen-nitrogen mixtures. Lower and upper flammability limits (mixing fan on, turbulent conditions) for ignition energies of 8 J are:Flammability limits of methane-nitrous oxide-nitrogen mixtures show no pronounced dependence on small amounts of oxygen (< 5%). Generally speaking, flammable gases with large initial amounts of nitrous oxide or ammonia show a strong dependence of flammability limits on ignition energy.