Card Rulings:Goblin of Greed


 * "Goblin of Greed" prevents discarding as a cost, but not as part of an effect. So "Goblin of Greed" will stop "Kuriboh", but not "Mirage of Nightmare" or "Graceful Charity".


 * If your opponent activates an effect and discards as a cost, and you chain "Call of the Haunted" to Special Summon "Goblin of Greed", he doesn't stop the effect because the cost was already paid.