add_gameplay_effect_modifier
Append a constant-magnitude modifier to a GameplayEffect Blueprint's Modifiers array and save it, without recompiling or creating an undo entry.
Instructions
Append one modifier with a constant magnitude to the Modifiers array on the class default object of a GameplayEffect Blueprint, then save it without recompiling and without an undo entry. attribute_name is looked up across every loaded AttributeSet class; an unknown attribute or modifier_op, a running PIE session or a read-only root fails before any edit. Each call appends a new entry, even an identical one; modifier_index says where it went. Change its magnitude type with set_gameplay_effect_modifier_set_by_caller, set_gameplay_effect_modifier_attribute_based or set_gameplay_effect_modifier_custom; remove_gameplay_effect_modifier drops it; get_gameplay_effect_modifiers lists them.
Returns: { ge_blueprint_path: string, attribute_name: string, modifier_op: string, magnitude: number, modifier_index: int, modifier_count: int, magnitude_readback_ok: bool, magnitude_readback: number, added: bool }
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| magnitude | Yes | Constant magnitude of the modifier, stored as a ScalableFloat without a curve | |
| modifier_op | Yes | Add, Multiply, Divide, or Override (case-insensitive) | |
| attribute_name | Yes | Attribute to modify, Health or MySet.Health: the bare name or AttributeSetClass.Attribute, case-insensitive, first match among the loaded AttributeSet classes | |
| blueprint_name | No | Alias of `ge_blueprint_path` (same value, same meaning). Accepted because sibling tools spell this parameter differently; prefer `ge_blueprint_path`. | |
| ge_blueprint_path | No | Full asset path of the GE Blueprint |