Goat format ruling
Goblin of Greed

Card effect (current official text)As long as this card remains face-up on your side of the field, neither player can activate an effect by discarding from his/her hand.
Rulings
- 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.
- Q: I have a face-up "Goblin of Greed" and it has survived until my next turn. I then summon "Tribe- Infecting Virus." Opponent passes on countering. I then choose to use "Tribe-Infecting Virus’s" effect. Would I have to discard a card to use "Tribe-Infecting Virus's" effect or would "Goblin of Greed" let me have free reign and just start picking all opponent's types of monsters (as long as they are not the same as mine..wouldn't want to destroy myself)? A: You would not be able to activate the effect of "Tribe-Infecting Virus" while "Goblin of Greed" is face-up on the field. The "Goblin of Greed's" effect prevents the discarding of a card as a cost, which is necessary to activate the "Tribe-Infecting Virus'" effect.
- Q: I have a face-up "Goblin of Greed." I then activate "Tribute to the Doomed"/"Dark Core." Would I have to discard a card to use those effects? A: You would not be able to activate either "Dark Core" or "Tribute to the Doomed."
- Q: I have a face-up "Goblin of Greed." My opponent activates "Raigeki." I chain with "Spell Shield Type- 8"/"Magic Jammer." Do I need to discard a card? A: You would not be able to activate either effect.
- Q: If there is a face-up "Goblin of Greed" on the field, can a player discard "Kuriboh" from his/her hand to reduce the damage from an attack to 0? A: Neither player would be able to discard a "Kuriboh." The attack would go through.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Goat forum — sourced change requests get reviewed.