Dice Dungeon (BLCR-EN005) [Battles of Legend: Crystal Revenge]

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.
<br>• 1: Lose 1000 ATK.
<br>• 2: Gain 1000 ATK.
<br>• 3: Lose 500 ATK.
<br>• 4: Gain 500 ATK.
<br>• 5: Halve their ATK.
<br>• 6: Double their ATK.