So I was playing a game of LoL when it suddenly says that "Your team scored an Ace!" I have never seen an Ace before, is this new in 4.20?
Some people say its an acronym for All Champions Eliminated
But in other languages like german, it's "Ass", which is the translation of ace (term from playing cards).
This is not new. The anouncer says this when all champions of a team are dead. You don't get any bonuses from it, like gold.