This study presents a brief overview of regularized and non-smooth methodologies for modeling frictional contact events in multibody dynamics. In regularized methods, the contact zone between colliding bodies can deform, and the contact forces are described by a continuous function of the local penetration between the contacting surfaces. The contact forces prevent interpenetration without the use of explicit kinematic constraints; instead, contact reaction forces are employed. The local pseudo-penetration plays a key role, as it is used to evaluate the contact forces based on an appropriate constitutive law. Furthermore, friction can be readily incorporated into continuous methods by employing a regularized friction force model. In turn, non-smooth approaches treat the colliding bodies as perfectly rigid, and contact dynamics are resolved by applying unilateral constraints to prevent penetration. The central idea of non-smooth formulations is the non-penetration condition, which prevents bodies from moving toward one another but not apart, reason why this approach is called unilateral constraint. For this, a complementarity formulation is used here to describe the relationship between the contact force and the gap distance at the contact point. These contact formulations are utilized to model and simulate the operation of a woodpecker toy benchmark problem. The integration of multibody systems with frictional contacts is particularly important not only for accurate dynamic analysis, but also for ensuring computational efficiency. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2026.