Dice Dungeon (Ultra Rare) [BLCR-EN005-UR]

When this card is activated: You can add 1 "Dimension Dice" from your Deck to your hand. At the start of the Battle Phase: You can activate this effect; each player rolls a six-sided die and applies the result to all monsters they control, until the end of this turn.
• 1: Lose 1000 ATK.
• 2: Gain 1000 ATK.
• 3: Lose 500 ATK.
• 4: Gain 500 ATK.
• 5: Halve their ATK.
• 6: Double their ATK.