| 4/8/2016 |
You may reveal any land card with either or both of the appropriate subtypes. It doesn't have to be a basic land. For example, you could reveal Sunken Hollow from the Battle for Zendikar set to satisfy the ability of Forboding Ruins. |
| 4/8/2016 |
Lands don't have a subtype just because they can produce mana of the corresponding color. Forboding Ruins itself is neither a Swamp nor a Mountain, even though it produces black and red mana, so you can't reveal one to satisfy the ability of another. |
| 4/8/2016 |
If a Swamp or Mountain is entering the battlefield from your hand at the same time as Forboding Ruins, you may reveal the other land to have Forboding Ruins enter untapped. |
| 4/8/2016 |
If an effect instructs you to put Forboding Ruins onto the battlefield tapped, it will still enter the battlefield tapped even if you reveal a land card from your hand. |
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