Channeling

Channeling an ability causes the caster to stop acting for the duration of the spell. Channeled spells may be ended when the channeling unit takes another action or is interrupted by another spell. While spells are being channeled, a draining bar will appear on the screen, indicating how much time is left in the channel.

Interrupting channeled abilities
If the channeling unit is issued another command, such as to move, stop, or attack, the unit will disrupt the channeled ability. Casting other spells or using items will also interrupt channeling, with the exception of toggled abilities, Wind Walk, a few other abilities like and the items below.

The only items that may be activated while channeling are, , , (switching only), , , , , , ,  and. Activating any other item, including, or consumables will interrupt channeling.

Any disable that would normally prevent a unit from casting the spell in question will also interrupt channeling. This includes Stuns, Mini-stuns, Cyclones, Hexes, Sleeps and getting hidden. Though they do not prevent casting, most Root effects will also interrupt channeling. Silence will interrupt channeling from abilities only, while and  (with ) will interrupt channeling from items as well. Some spells that forcibly move units, such as or  (the first applies a ministun while moving units, and the second one is like an uncontrollable blink), will interrupt channeling as well, even if used on friendly units, however, other spells like  and, will not interrupt channeling, because they just give a little push to their targets.

If the channel is interrupted before the spell's effects occur, the mana and cooldown will be wasted, and the spell's effect will be cut short, and in some cases will not perform their effects at all. This is in contrast to other, non-channeled spells with high cast times, such as and, which will not expend mana or go on cooldown until the spell has been completed. Certain channeled spells, such as and, will still perform their effect even if they are cancelled, usually at the cost of damage.