Abstract <p>The study of the first-order magnetic phase transition mechanisms is one of the key challenges in modern physics. The difficulty in identifying these mechanisms arises from the multitude of factors that play a significant role during the phase transition. FeRh-based alloys are among the most typical systems exhibiting a first-order phase transition from the antiferromagnetic to the ferromagnetic state. Despite the fact that the iron–rhodium alloy possesses a relatively simple crystal structure and does not change the symmetry of its crystal lattice during the phase transition, a number of features in the behavior of its physical properties are observed. This review presents present-day information on the influence of various external factors, the effects of crystalline defects, and dimensional characteristics on the static and dynamic properties of FeRh-based alloys.</p>