  We extend the study of scattering amplitudes presented in ``The LHC String
Hunter's Companion'' to the case of five-point processes that may reveal the
signals of low mass strings at the LHC and are potentially useful for detailed
investigations of fundamental Regge excitations. In particular, we compute the
full-fledged string disk amplitudes describing all 2->3 parton scattering
subprocesses leading to the production of three hadronic jets. We cast our
results in a form suitable for the implementation of stringy partonic cross
sections in the LHC data analysis. We discuss the universal, model-independent
features of multi-parton processes and point out the existence of even stronger
universality relating N-gluon amplitudes to the amplitudes involving N-2 gluons
and one quark-antiquark pair. We construct a particularly simple basis of two
functions describing all universal five-point amplitudes. We also discuss
model-dependent amplitudes involving four fermions and one gauge boson that may
be relevant for studying jets associated to Drell-Yan pairs and other processes
depending on the spectrum of Kaluza-Klein particles, thus on the geometry of
compact dimensions.
