  In the current view of Gamma-Ray Burst (GRB) phenomena, an emission component
extending up to the very-high energy (VHE, E > 30 GeV) domain is though to be a
relatively common feature at least in the brightest events. This leads to an
unexpected richness of possible theoretical models able to describe such
phenomenology. Hints of emission at tens of GeV are indeed known since the
EGRET observations during the '90s and confirmed in the Fermi-LAT data.
However, our comprehension of these phenomena is still far to be satisfactory.
In this respect, the VHE characterization of GRBs may constitute a breakthrough
for understanding their physics and, possibly, for providing decisive clues for
the discrimination among different proposed emission mechanisms, which are
barely distinguishable at lower energies. The current generation of Cherenkov
observatories, such as the MAGIC telescopes, have opened the possibility to
extend the measurement of GRB emission, and in general to any short time-scale
transient phenomena, fromfew tens of GeV up to the TeV energy range, with a
higher sensitivity with respect to gamma-ray space-based instruments. In the
near future, a crucial role for the VHE observations of GRBs will be played by
the Cherenkov Telescope Array (CTA), thanks to its about one order of magnitude
better sensitivity and lower energy threshold with respect to current
instruments. In this contribution, we present a method aimed at providing VHE
detection prospects for observations of GRB-like transient events with
Cherenkov telescopes. In particular, we consider the observation of the
transient event GRB 090102 as a test case for the method and show the achieved
detection prospects under different observational conditions for the MAGIC
telescopes and CTA.
