At the beginning of combat on your turn, you may pay . If you do, support 2. (Put a +1/+1 counter on each of up to two other target creatures.)
The competition is but one aspect of the spectacle.
(08/06/2018)
If some, but not all, targets for a spell become illegal, the remaining targets are affected as appropriate. If all of a spell's targets become illegal, that spell doesn't resolve.
(08/06/2018)
You can't put more than one +1/+1 counter on any one target using the support action.
(08/06/2018)
If a spell with support has other abilities that target creatures, those abilities and the support ability can target the same creature.
(08/06/2018)
You choose the target creatures to support when Jubilant Mascot's triggered ability is put onto the stack, but you don't choose whether to pay until the ability resolves.
(08/06/2018)
Support can target a creature another player controls.
