/attribute: base value versus modifiers, and why yours keeps resetting
Setting a base value is permanent and setting a modifier is not — unless you pick the wrong operation. The three operations, the stacking order, and the slot trap.
/attribute looks like one command with three subcommands. It is really two different systems that happen to share a name, and mixing them up is why values keep snapping back.
base versus modifier
/attribute @s minecraft:max_health base set 40
/attribute @s minecraft:max_health modifier add my_buff 20 add_valuebase setrewrites the entity's own value. It persists through reloads and is
not removed by anything except another base set.
modifier addlayers a temporary adjustment on top. It has an id, and it can be
removed by that id.
If your change disappears on relog, you used a modifier and something cleared it. If your change will not go away, you used base set and need base reset.
The three operations, and the order they apply
| Operation | Does | Applied |
|---|---|---|
add_value | value + n | first |
add_multiplied_base | value + (base × n) | second |
add_multiplied_total | running total × (1 + n) | last |
The order is fixed and it matters. Starting from base 20, then add_value 10 and add_multiplied_total 0.5:
20 → 30 → 45 not 20 → 30 → 30 + 10 = 40add_multiplied_base always multiplies the original base, not the running total — which is why two of them stack additively rather than compounding.
Modifier ids are namespaced now
Older versions used a UUID. Modern versions use a namespaced id:
/attribute @s minecraft:attack_damage modifier add my_pack:rage 5 add_valueAdding a second modifier with the same id replaces the first rather than stacking. That is the intended way to refresh a buff — you do not need to remove it first.
Equipment modifiers live on the item, not the entity
An enchanted sword's damage bonus is an attribute_modifiers item component, and it only applies while the item is in the right slot:
/give @s diamond_sword[attribute_modifiers=[{type:"attack_damage",amount:5,
operation:"add_value",slot:"mainhand",id:"my:bonus"}]]slot is required and is the usual mistake. Omit it and the modifier applies in every slot, so a sword in your inventory buffs you while it sits there.
Valid slots: mainhand, offhand, head, chest, legs, feet, armor, body, any.
Reading a value back
/attribute @s minecraft:max_health getreturns the base, not the effective total. To get the total including modifiers, use execute store result on a scoreboard and read that.
Build any of these — including the item-component form with the slot set — in the Entity & Combat Command Builder.