Stormscale Anarch — ruling 1

You can't discard a card at random, see what it is, and then decide whether or not to pay the mana. Mana abilities must be activated before costs are paid. At the time you pay the cost of discarding a card, you either have enough mana to pay the {2}{R}, in which case you must continue no matter what you discarded, or you don't have enough mana to pay the {2}{R}, in which case you must back up no matter what you discarded.

Stormscale Anarch : règles, fonctionnement et interactions (MTG)

Stormscale Anarch 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

, Discard a card at random: This creature deals 2 damage to any target. If the discarded card was multicolored, this creature deals 4 damage instead.

How it works : Stormscale Anarch

Original English text — Wizards of the Coast / Scryfall

#1May 1, 2006· Wizards of the Coast
You can't discard a card at random, see what it is, and then decide whether or not to pay the mana. Mana abilities must be activated before costs are paid. At the time you pay the cost of discarding a card, you either have enough mana to pay the , in which case you must continue no matter what you discarded, or you don't have enough mana to pay the , in which case you must back up no matter what you discarded.
No other card is named in this ruling.