Final answer:
The three forces involved in a tug-of-war are tension, friction, and weight forces.
Step-by-step explanation:
In a tug-of-war, there are three forces at play: tension force, friction force, and weight force. The tension force is the force exerted by the rope on the teams in opposite directions. The friction force is the force between the teams' feet and the ground that prevents them from slipping. The weight force is the force due to gravity acting on the teams' masses.
For example, when the two teams are pulling on the rope, the tension force in the rope increases. If one team pulls harder than the other, the tension force will be unbalanced, causing the rope to move towards the side of the stronger team.