High TideHow it works & interactions with other cards

What It Does

High Tide creates a delayed triggered ability that lasts until the end of the current turn. Whenever any player taps a land with the 'Island' subtype for mana, that player adds one extra blue mana to their mana pool. This effect is not restricted to basic Islands; it applies to any land that has the Island land type in its type line, such as dual lands or triomes.

How It Resolves Step by Step

First, you cast High Tide for one blue mana. Once it resolves, the game state is modified for the remainder of the turn. Every time you tap an Island for mana, the original mana ability of the land goes on the stack (or resolves immediately if it is a mana ability), and the High Tide triggered ability adds an additional {U}. If you cast multiple copies of High Tide in a single turn, each one triggers independently, meaning two copies will result in two additional blue mana per Island tapped.

Common Mistakes

A frequent error is assuming High Tide only affects basic Islands. As long as the land has 'Island' printed on its type line, it will trigger the effect. Another common mistake is forgetting that the effect applies to all players; if you cast High Tide and your opponent taps an Island on your turn, they also receive the extra mana. Finally, remember that High Tide does not double all mana the land produces; it specifically adds one {U}, regardless of how much or what color mana the land originally produced.

When to Play It

High Tide is most effective when you have several Islands in play and a hand full of spells. Because it is an instant, you can cast it in response to an opponent's action to ensure you have enough mana for counter-magic. However, it is usually reserved for a 'combo turn' where you intend to generate a large surplus of mana to finish the game.

Interaction examples

Building a Mana Buffer

Counterspell

You have two basic Islands untapped. You cast High Tide using one Island, leaving one Island open. Because High Tide has resolved, if you now tap that second Island for mana, it produces {U}{U} instead of just {U}. This allows you to cast Counterspell using only a single land, effectively saving your resources for further plays.

Mitigating Drawbacks

An Offer You Can't Refuse

After resolving High Tide, you tap two Islands to generate four blue mana. You use one mana to cast a spell and hold three in reserve. When your opponent tries to stop you, you cast An Offer You Can't Refuse. Even though you give your opponent two Treasures, the massive mana advantage generated by High Tide ensures you have plenty of mana left to continue your turn despite the interaction.