Effective theories are helpful tools to gain an intuitive insight into phen
omena governed by complex laws. In this work we show by means of Monte Carl
o simulations that Z(2) spin models with only spin-spin interactions approx
imate rather well the critical behavior of SU(2) gauge theory at finite tem
perature. These models are then used to formulate an effective description
of Polyakov loop percolation, which is shown to reproduce the thermal criti
cal behaviour of SU(2) gauge theory. (C) 2001 Published by Elsevier Science
B.V.