Official rule text
55.2 Each player begins with their mech unit card in play on their b The ship cannot move through a system that contains ships leader sheet and can produce mechs for the cost presented on that are controlled by another player. the card. c The ship cannot move if it started its movement in another
View official source
Source: Twilight Imperium: Fourth Edition - Living Rules Reference: Prophecy of Kings
Expansion: Prophecy of Kings
Version: 2.0
Reference: Rule 55.2