When Volibear attacks, can you choose not to trigger his 5 split damage ability (for example, to avoid paying for Deflect)?

Ruling: You can choose to have the ability not enter the chain if you would have to pay an additional cost like Deflect.

Nuances:

• When interacting with Reaver's Row, Reaver's Row will resolve first, so the target can leave the battlefield and take no damage.