When playing a spell in a multiplayer game, at what point must you designate the target, and does it need to be announced before opponents can react?

Ruling: You must choose the target when the spell goes on the chain, before giving other players the opportunity to react.

Nuances:

• Any time you (and only you) have to choose an object on the board, it targets
• Effects that automatically select objects are not targeting (example given: Ahri Legend)
• Effects like 'stun a unit' are targeting because you choose the unit