effect · set_global_flag

Hands-On Usage

set_global_flag is commonly used to track global narrative states across countries and events, such as marking a historical event as triggered or a world-level mission as completed. Since it operates in the global namespace, any country scope can read it, making it ideal for multi-nation collaborative scripts or achievement unlock logic.

# When a country completes nuclear weapon research, set a global flag for other country events to detect
country_event = {
    id = my_mod.1
    option = {
        name = my_mod.1.a
        set_global_flag = first_nuclear_power_emerged
    }
}

Synergy

• [has_global_flag](/wiki/trigger/has_global_flag): After setting a global flag, this trigger is typically paired in trigger blocks of other events or focuses to check whether the flag exists, forming a "write-read" closed loop.
• [clr_global_flag](/wiki/effect/clr_global_flag): When a narrative phase concludes or state needs to be reset, use this command to clear previously set flags and prevent them from permanently lingering and affecting subsequent logic.
• [modify_global_flag](/wiki/effect/modify_global_flag): If you need to attach numerical values to a flag (such as a counter), use this command to modify an existing flag, combined with set_global_flag to implement stateful global counting.
• [hidden_effect](/wiki/effect/hidden_effect): Wrap set_global_flag inside a hidden effect block to prevent players from seeing unnecessary internal state change notifications in event options.

Common Pitfalls

1. Inconsistent flag name spelling: The flag names used in set_global_flag and has_global_flag / clr_global_flag must match exactly (case-sensitive). If a typo changes the capitalization or underscores anywhere, the trigger will never detect that flag, and the game won't report an error, making it extremely difficult to debug.
2. Mistakenly using global flags instead of country flags: Global flags are visible to all countries and only have one instance. If you only want to record the state of a specific country, use set_country_flag instead of set_global_flag. Otherwise, multi-playthrough or multi-nation coexistence scenarios will cause state pollution.