Mexican Train: each player builds a personal train from a central double, plus a communal train anyone may extend.; All Fives (Muggins): score whenever the open ends total a multiple of five.; Chicken Foot: a played double must be surrounded by three tiles before normal play resumes.
Why people argue about this
People often assume that in Mexican Train, you can only build your own train from a central double without considering the communal aspect where anyone's train can be extended by others. The confusion arises because they overlook how the official rules allow for both personal and communal trains to coexist and grow simultaneously.