effect · set_fuel_ratio

Hands-On Usage

set_fuel_ratio is commonly used in events or decisions to immediately adjust a nation's fuel storage ratio, such as rewarding players with "emergency fuel resupply" or simulating a fuel crisis when triggered by a scenario. It accepts a decimal value between 0 and 1, setting the current stockpile directly to the corresponding proportion of capacity rather than applying an incremental change.

# Event option: receive emergency fuel resupply, replenish fuel ratio to 80%
option = {
    name = my_event.1.a
    set_fuel_ratio = 0.8
}

# Decision effect: simulate a fuel crisis, reduce fuel ratio to 10%
immediate = {
    set_fuel_ratio = 0.1
}

Synergy

• [fuel_ratio](/wiki/trigger/fuel_ratio): Check the current fuel ratio with this trigger before executing set_fuel_ratio to ensure resupply rewards only trigger when fuel is insufficient, avoiding waste.
• [add_fuel](/wiki/effect/add_fuel): These two complement each other—set_fuel_ratio is absolute assignment while add_fuel is relative increment; use the former when you need precise ratio targets and the latter for dynamic adjustments.
• [add_dynamic_modifier](/wiki/effect/add_dynamic_modifier): After adjusting the fuel ratio, you can apply a dynamic modifier simultaneously to simulate the ongoing impact of adequate/insufficient fuel on combat efficiency, creating a complete logical chain.
• [country_event](/wiki/effect/country_event): Trigger subsequent events after adjusting the fuel ratio to notify the player of status changes or advance story branches.

Common Pitfalls

1. Writing the value as a percentage integer: Beginners often write set_fuel_ratio = 80 instead of set_fuel_ratio = 0.8. The game won't error but will clamp the fuel ratio directly to the maximum (1.0), producing results completely contrary to expectations and making the issue difficult to detect.
2. Misusing it under STATE or CHARACTER scope: This command only works in COUNTRY scope. If called within scope blocks of owned_state or unit leaders, the effect silently fails without any error message, making it extremely easy to overlook during debugging.