equilibrium. The latter is referred to as the *stable state*. Classical examples are supersaturated vapours, supercooled liquids, and ferromagnets in the hysteresis loop. The main three objects of interest for metastability are the transition time from the metastable state to the stable state, the gate of configurations the system has to cross in order to achieve the transition, and the tube of typical trajectories the system follows prior to and after the transition.

Metastability for interacting particle systems on *lattices* has been studied intensively in the past three decades. Various different approaches have been proposed. After initial work by Cassandro, Galves, Olivieri and Vares [@CGOV84], Neves and Schonmann [@NS91], [@NS92], a powerful method – known as the *pathwise approach* to metastability based on large deviation theory – was developed in Olivieri and Scoppola [@OS95], [@OS96], Catoni and Cerf [@CC97], Manzo, Nardi, Olivieri and Scoppola [@MNOS04], Cirillo and Nardi [@CN13], Cirillo, Nardi and Sohier [@CNSo15]. This was successfully applied to low-temperature Ising and Blume-Capel models subject to Glauber spin-flip dynamics (in two and three dimensions, with isotropic, anisotropic and staggered interactions) in Kotecký and Olivieri [@KO92], [@KO93], [@KO94], Cirillo and Olivieri [@CO96], Ben Arous and Cerf [@BAC96], Nardi and Olivieri [@NO96]. 