Courier

A Courier is a unit that transports items from the shops to the heroes. Every player gets a courier at the beginning of the match. The courier starts out walking, but gains the ability to fly at higher levels.

Leveling
A player's courier levels up as the player's hero does. With each level, the courier gains additional 10 movement speed, and 10 health.

On the other side, each level also increases the courier's gold bounty and respawn time by 7 seconds.

Besides these level bonuses, certain levels have additional effects:
 * Level 5: The courier gains a pair of wings, turning into a flying unit with flying vision.
 * Level 10: Unlocks the ability.
 * Level 20: Unlocks the ability.

Inventory
Like a hero, the courier possesses 6 inventory slots and 4 backpack slots. However, before reaching level 25, it has restrictions. Every item gets muted when in the courier's inventory, rendering all their stats and abilities disabled and unusable for the courier. Muted items are darkened out in its inventory.

However, even if no longer muted, some items still have courier-specific restrictions. The following items have restrictions:
 * : Casting does nothing but trigger the cooldown. The courier cannot pick up runes with the bottle at all.
 * : The True Sight ability is fully disabled for courier-type units, so the courier can never provide True Sight, even if not muted.
 * : Casting does nothing but trigger the cooldown, without consuming the item.

Besides these restrictions, the courier is also unable to pick up, , and. A courier may only hold a Divine Rapier when it got combined in its inventory. It may not be given a rapier by another unit, and it may not pick up any rapiers from the ground.

Items which drop on death are dropped by the courier as well if killed while carrying such items. Items which cannot be placed in backpacks may not be placed in the courier's backpack either.

Turbo Mode
In Turbo Mode, the courier starts at level 6, so that it is always flying. It also has a fixed movement speed of 1100, and cannot be directly controlled by the player. It can still be ordered around using the abilities, like a regular courier, but does not accept any other move orders. The courier automatically delivers items to the player, checking the stash in 5 second intervals. This auto-deliver can be toggled on and off, with the ability. Since the courier has a fixed movement speed value, it does not have the ability, the Auto Deliver toggle ability takes its place instead.

The Turbo Mode courier's inventory follows the same rules as the default courier. Items are muted until reaching level 25, and wards may be placed at level 15.

Spell interactions
Couriers are spell immune and ancient units, so that their spell interactions fully apply.

On top of these two, the courier has its own unique type, which prevents certain spells from affecting it. These lists contain only interactions caused by this unit type, ignoring the spell immunity and ancient unit type. This means all spells not listed can affect couriers, but may be prevented by their spell immunity or ancient unit type. This also means spells listed in here would still be unable to affect couriers, even if they pierce spell immunity or are able to affect ancient units.

Couriers are not considered heroes, meaning they are completely unaffected by hero-only spells, just like regular creeps.

Morphing from the to the  replaces the unit, which results in the courier avoiding any attacks, including melee attacks, targeted at the old unit.

The behaves the same as the, with the exception of. They are not triggered by flying units, nor do they take damage.


 * Spells marked with one asterisk (*) are also prevented by spell immunity.
 * Spells marked with two asterisks (**) are also prevented by the ancient unit type.

These abilities have mixed behaviors with couriers: