effect · `multiply_variable`

Definition

Supported scope:any
Supported target:none

Description

Multiplies a variable by a value, another variable, or a [math expression](script_math_expression.md).

### Examples

multiply_variable = { num_dogs = 2 } multiply_variable = { num_dogs = { value = num_cats add = 1 } }

实战 · 配合 · 坑

实战内容由 AI 生成,并已对照 vanilla 命令词表校验 —— 请当作起点而非权威依据。上方的定义节才是游戏自带文档原文。

实战用法

multiply_variable 常用于动态数值缩放场景，例如根据某项加成系数对已积累的资源变量进行乘法放大，或在科研/经济 mod 中将基础产量乘以效率倍率。下例演示将 production_output 变量乘以 1.5 的效率系数：

# 在某事件的 option 块中，将产量变量扩大为原来的 1.5 倍
multiply_variable = {
    var = production_output
    value = 1.5
}

配合关系

[set_variable](/wiki/effect/set_variable)：通常先用 set_variable 初始化变量的基础值，再用 multiply_variable 对其做倍率调整，两者构成"赋初值→缩放"的标准流程。
[add_to_variable](/wiki/effect/add_to_variable)：乘法与加法组合可实现"先乘后加"的复合公式，模拟带固定增量的线性缩放逻辑。
[check_variable](/wiki/trigger/check_variable)：乘法运算后通常需要检验结果是否越过某个阈值，用 check_variable 作条件判断可防止数值失控。
[clamp_variable](/wiki/effect/clamp_variable)：对乘法结果立即做上下界夹紧，避免极端倍率导致变量溢出或产生不合理的游戏状态。

常见坑

忘记变量未初始化就直接相乘：若目标变量从未被 set_variable 赋值，其默认值为 0，乘以任何数仍为 0，不会报错但结果完全静默地出错，新手很难察觉。
将 value 写成变量名字符串而非数值或 var:xxx 引用：value 字段若要引用另一个变量应写 value = var:some_var，直接写裸字符串会导致脚本解析失败或被当作 0 处理。

Hands-On Notes

Hands-on notes are AI-generated and checked against the vanilla command vocabulary — treat them as a starting point, not authoritative reference. The definition above is the game's own documentation.

Hands-On Usage

multiply_variable is commonly used in dynamic value scaling scenarios, such as amplifying accumulated resource variables by a modifier coefficient, or multiplying base output by an efficiency multiplier in research/economy mods. The following example demonstrates multiplying the production_output variable by an efficiency coefficient of 1.5:

# In an option block of an event, scale the production variable to 1.5 times its original value
multiply_variable = {
    var = production_output
    value = 1.5
}

Synergy

[set_variable](/wiki/effect/set_variable): Typically use set_variable first to initialize the base value of a variable, then apply multiply_variable to adjust it by a multiplier. These two form the standard "initialize → scale" workflow.
[add_to_variable](/wiki/effect/add_to_variable): Combining multiplication and addition enables "multiply then add" composite formulas, simulating linear scaling logic with a fixed increment.
[check_variable](/wiki/trigger/check_variable): After multiplication operations, you typically need to verify whether the result crosses a certain threshold. Using check_variable as a conditional check prevents numerical runaway.
[clamp_variable](/wiki/effect/clamp_variable): Immediately clamp the multiplication result within upper and lower bounds to prevent extreme multipliers from causing variable overflow or unrealistic game states.

Common Pitfalls

Multiplying without initializing the variable first: If the target variable has never been assigned a value by set_variable, its default value is 0. Multiplying by any number still yields 0, which won't throw an error but silently produces incorrect results—easily missed by beginners.
Writing value as a bare variable name string instead of a numeric literal or var:xxx reference: If the value field needs to reference another variable, write it as value = var:some_var. Using a bare string causes script parsing failure or gets treated as 0.

effect · multiply_variable