Two Rules Bugs that are not Consistent with MTGA but Would be Legal in Paper Magic
Talking with a level 5 judge, there seems to be some rules errors that MTGA has had since BRO was released (I have yet to reconfirm this since Alchemy BRO and this week’s update).
0) My opponent should have won this game. I unfortunately don’t know what buttons they pressed. They clearly looked to try to do the following and still lost the game, because they couldn’t pay:
The turn prior, opponent casts !Pact of Negation. Moving to the next turn's upkeep with the trigger on the stack and Goblin Charbelcher in play: opponent responds with the Charbelcher to deal damage and try to win the game (assuming they only have spells in their deck). MTGA said opponent lost. Level 5 judge and I agreed they should have won, because they could have had time to respond to PoN’s taxation trigger.
1) Attacking into a player with Nine Lives and having the potential damage to win if Nine Lives wasn’t in play. I Stomp opponent before creatures deal combat damage. (MTGA doesnt support this line of play)
That “If I attack the Nine Lives opponent for 10, and opponent is at 10 life with the Lives in play; casting Stomp, opponent takes 12 damage since the Lives does not prevent the damage because of Stomp; opponent should be at -2 life and lose the game.” (level 5 judge but do check as well)
[as an aside, normally you encounter this with Serra's Emissary naming creature. That you can Stomp and by pass the ‘prevent damage’ part of the protection effect. In the past this has worked correctly, Stomp > Serra’s Emissary’s Protection. Thus please review ‘can’t be prevented’ clauses with Nine Lives]