  All-order strong coupling simulations have been used to derive precise
energies of string states in the confined phase of three dimensional Z(2)
lattice gauge theory. The behavior of the ground state energy is here compared
with predictions of effective string theory. Our new data reported here are
consistent with known universal terms of the long string length ($L_0$)
expansion known from effective string models in the continuum limit. Our
precision is however still not sufficient to disentangle non-univeral terms of
order $L_0^{-7}
