A comprehensive statistical mechanics treatment of (non)interacting de
formable planar droplets of arbitrary rigidity is developed. Closed fo
rm exact analytic results are obtained for the area statistics of a si
ngle droplet and for the decay rates of metastable states characterist
ic of the first-order phase transitions for an assembly of such drople
ts. To select the correct form of the interaction between the droplets
, the reparametrization invariance is taken into account. Most of the
known two-dimensional lattice models are obtained as the limiting case
s of the interacting droplet model discussed in the text. (C) 1996 Ame
rican Institute of Physics.