Snag

A Fog with a discount clause, and the discount tells you exactly what this design was reaching for. The set's whole gimmick was a cycle of spells you could cast for free by pitching a land of the matching type, trading a card and a land drop for mana you didn't have. Here that means a green deck flush with Forests can hold up a damage-prevention spell with no mana invested, an attractive proposition until you do the arithmetic. The base rate is brutal: four mana for an effect Fog delivered for one back in Alpha, and a narrower one at that, since this prevents only damage from unblocked creatures rather than all combat damage. Pitching a Forest is the card's entire pitch, and it's a bad one, because you are throwing away a land you wanted in play to avoid a cost you could not realistically afford anyway. The free-spell-gated-behind-land-discards idea reads better on paper than at the table, where discarding lands to dodge mana costs runs directly counter to wanting to develop your board. The result is a Fog that loses to Fog by every measure except the fantasy of casting it for zero, a fantasy that costs you the Forest you would rather have kept.