The tide is a game state represented by the Tide reference card, which is included with some KeyForge decks. If one or more KeyForge decks used in a game include a Tide reference card, then all players can interact with, and be affected by, the tide.
The tide reference card helps players track whether the tide is high or low for them, and to serve as a reminder that they have access to the “Omni:” ability to raise the ride.
At the start of each game, the tide is neutral (neither high nor low). When either player raises the tide, the tide becomes high for them and low for their opponent. If the tide is already high for a player, they cannot raise the tide.
During the active player’s turn, they may use the ability “Omni: Raise the tide. Gain 3 chains.” This ability is granted by the game rules and not by a card ability. Unlike most “Omni:” abilities, this ability does not require a player to exhaust any card. A player can use this ability any number of times in a turn.
When a card effect instructs a player to raise the tide, they should rotate the Tide reference card such that the side labeled “High Tide” is facing them and the side labeled “Low Tide” is facing their opponent.
Card abilities that refer to the tide are indicated by this icon:
Yes, a player can still use the Tide's Omni: ability even when the tide is already high for them, which will have no affect on the tide, but will give them chains. So yes, that means that players can use this to chain themselves repeatedly in the rare instances where they might want to do that.Source