  We present an alternative quantization for irreducible open gauge theories.
The method relies on the possibility of modifying the classical BRST operator
and the gauge-fixing action written as in Yang-Mills type theories, in order to
obtain an on-shell invariant quantum action by using equations characterizing
the full gauge algebra. From this follows then the construction of an off-shell
version of the theory. We show how it is possible to build off-shell BRST
algebra together with an invariant extension of the classical action. This is
realized via a systematic prescription for the introduction of auxiliary
fields.
