General DiscussionHow to use autocast?

You mean stuff like lich armor or ogre bloodlust? Or orb effects like searing arrows, frost arrows, silencer glaives etc?

2nd mouse click on spell

sorry, i mean quick cast -__________________-

Go in setting
ability (or what ever name it is for changing shortcut) and then you'll see,
Ability 1
Ability 2
...
auto-ability 1
auto-ability 2
....
fast-cast ability 1
fast-cast ability 2
or what ever it's called
normally that the one you want to put hotkey on

you mean the smart cast that LoL has? i guess you have to assign it like matrice mentioned above, then you use your mouse to hover over the player/aoe and click the ability and tada.

A quick explanation of quick cast (lawl); Let us take Scythe of Vyse for example:

[*]Normally, you would activate your scythe, mouse over your target, then right click your target and your target would be hexed.
[*]With Quick cast, you would mouse of your target, then activate your Sycthe, and the target would be hex.

You basically have to make one less action to perform your cast, and in some situations you can perform an action faster. However there are many situations where doing this would be bad (preparing to blink etc...).