Hi.
We have a ongoing discussion about the Fight mechanic.

A controlls a Foe-Razer Regent and Bloodcrazed Goblin
N controlls Ajani's Sunstriker

A cast Prey Upon targeting Bloodcrazed Goblin and Ajani's Sunstriker. In response N cast Brave the Elements,

If N choses Green, making Sunstriker a ilegal target for Prey Upon, do the Fight still hapens (but with no damage being dealt)? relevant for Foe-Reaper Regent.

If N chose Red, making it a still legal target for Prey Upon but preventing the damage dealt to one side, does thisstill count as a Fight?


701.10a A spell or ability may instruct a creature to fight another creature or it may instruct two creatures to fight each other. Each of those creatures deals damage equal to its power to the other creature.

701.10b If a creature instructed to fight is no longer on the battlefield or is no longer a creature, no damage is dealt. If a creature is an illegal target for a resolving spell or ability that instructs it to fight, no damage is dealt.


Cheers
Jakob

A fight still happens even if the damage being dealt during it is prevented, so if N chose to give her Ajani's Sunstriker protection from red, Foe-Razer Regent would still trigger and put +1/+1 counters on Bloodcrazed Goblin if it lives long enough to receive them. (Which it won't unless player A does something to help it survive.)

However, if one or more of Prey Upon's targets is illegal, the fight never happens. If the Sunstriker was given protection from green instead, Prey Upon can't affect it, so it can't be made to fight. And if Ajani's Sunstriker isn't fighting Bloodcrazed Goblin, the Goblin isn't fighting the Sunstriker either. So the Regent will not trigger and the Goblin won't get any counters.