Land {T}: Add to your mana pool one mana of any type that a land you control could produce. Does it reflect the future that once was or the past that can never be?
Illus. Fred Fields
If none of your lands can produce mana, or if all of your lands are Reflecting Pools, then your Reflecting Pools can have their abilities played but they will not generate any mana. [Barclay 2003/10/29]
It does not care if you are currently unable to meet the costs or play requirements for a mana ability of the land. For example, if the land has a cost of removing a counter and it has no counter, or if the land can only produce mana on your turn. [Shadowmoor FAQ 2008/04/21]
It checks for types the land could produce under all possible conditions. For example, if a land can only produce mana if you pay a cost or if some condition is met, Reflecting Pool can still generate mana of that color. For example, Reflecting Pool can make green mana if Gaea's Cradle is in play with no creatures in play, or black mana if a Bottomless Vault is in play with no counters on it, or red mana if a Mountain is in play and tapped. [WotC Rules Team 1999/03/18] The rule about multiple Reflecting Pools not helping each other out is a special one. That is true since Reflecting Pool does not specify what mana it could produce, so the "perfect conditions" here result in confusion, which results in no mana types at all.
Any change to a land's type or splicing of text into a land can affect the types of mana a land can produce. [D'Angelo 1998/11/12]
The type of mana is whatever color(s) of mana could be produced after applying effects that might alter the color(s). [Shadowmoor FAQ 2008/04/21]
Any replacement effects, such as Naked Singularity, are considered by Reflecting Pool when determining the types of mana a land can produce. [WotC Rules Team 1998/03/18]
It does not copy any restrictions on how the mana is spent. [Shadowmoor FAQ 2008/04/21]
Shadowmoor
(Rare)