Official rule text
1.8 Abilities on components that remain in play are mandatory 1.22 The opening paragraph of each ability found on an action card unless those abilities use the word “may.” describes when a player can resolve that card’s ability.
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Source: Twilight Imperium: Fourth Edition - Living Rules Reference: Prophecy of Kings
Expansion: Prophecy of Kings
Version: 2.0
Reference: Rule 1.8