Raging Battle Mouse — ruling 1

Spells that were cast before Raging Battle Mouse entered the battlefield count. If Raging Battle Mouse was the first spell you cast this turn, the next spell you cast this turn is your second spell.

Raging Battle Mouse — ruling 2

Raging Battle Mouse can't reduce its own cost, even if it's the second spell you cast in a turn.

Raging Battle Mouse — ruling 3

Raging Battle Mouse's cost-reduction ability doesn't change the mana cost or mana value of any spell. It changes only the total cost you pay.

Raging Battle Mouse — ruling 4

Raging Battle Mouse's cost-reduction ability can't reduce the amount of colored mana you pay for a spell. It reduces only the generic mana component of that cost.

Raging Battle Mouse — ruling 5

Each celebration ability has a different effect.

Raging Battle Mouse — ruling 6

Some celebration abilities trigger at specific parts of the turn and check whether two or more nonland permanents entered the battlefield under your control already in that turn.

Raging Battle Mouse — ruling 7

Others are static abilities that give creatures abilities or power and toughness increases as long as two or more nonland permanents entered the battlefield under your control that turn.

Raging Battle Mouse — ruling 8

Celebration abilities only care if two or more nonland permanents entered the battlefield under your control in a turn. They won't get more powerful if more than two permanents entered the battlefield under your control in a turn.

Raging Battle Mouse : règles, fonctionnement et interactions (MTG)

Raging Battle Mouse is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

The second spell you cast each turn costs less to cast. Celebration — At the beginning of combat on your turn, if two or more nonland permanents entered the battlefield under your control this turn, target creature you control gets +1/+1 until end of turn.

How it works : Raging Battle Mouse

Original English text — Wizards of the Coast / Scryfall

#1September 1, 2023· Wizards of the Coast
Spells that were cast before Raging Battle Mouse entered the battlefield count. If Raging Battle Mouse was the first spell you cast this turn, the next spell you cast this turn is your second spell.
No other card is named in this ruling.
#2September 1, 2023· Wizards of the Coast
Raging Battle Mouse can't reduce its own cost, even if it's the second spell you cast in a turn.
No other card is named in this ruling.
#3September 1, 2023· Wizards of the Coast
Raging Battle Mouse's cost-reduction ability doesn't change the mana cost or mana value of any spell. It changes only the total cost you pay.
No other card is named in this ruling.
#4September 1, 2023· Wizards of the Coast
Raging Battle Mouse's cost-reduction ability can't reduce the amount of colored mana you pay for a spell. It reduces only the generic mana component of that cost.
No other card is named in this ruling.
#5September 1, 2023· Wizards of the Coast
Each celebration ability has a different effect.
No other card is named in this ruling.
#6September 1, 2023· Wizards of the Coast
Some celebration abilities trigger at specific parts of the turn and check whether two or more nonland permanents entered the battlefield under your control already in that turn.
No other card is named in this ruling.
#7September 1, 2023· Wizards of the Coast
Others are static abilities that give creatures abilities or power and toughness increases as long as two or more nonland permanents entered the battlefield under your control that turn.
No other card is named in this ruling.
#8September 1, 2023· Wizards of the Coast
Celebration abilities only care if two or more nonland permanents entered the battlefield under your control in a turn. They won't get more powerful if more than two permanents entered the battlefield under your control in a turn.
No other card is named in this ruling.
#9September 1, 2023· Wizards of the Coast
The permanents that entered the battlefield don't need to remain on the battlefield or under your control. Celebration abilities are checking for past events, not the current game state.
No other card is named in this ruling.