Flavor

A living battlefield, pick your battles carefully.

Expected play patterns

Provide the choice between mana producing lands and new abilities, act as a late game pseudo mana sink. Different Fronts should be useful in different situations. Both a single advanced Front and multiple Fronts should be viable.

Rulings

116.2i Advancing and retreating a Front are special actions. See rule 305.10.

305.10 Some lands have the subtype "Front". A Front can be in one of two states: retreated and advanced. It enters the battlefield in the retreated state.

305.10a Any time the active player has priority and the stack is empty, but only during a main phase of their turn, that player may advance a retreated Front or retreat from an advanced Front, changing its current state. Advancing a Front costs a player for each already advanced Front they control. A player cannot both advance and retreat the same Front in a single turn. These are special actions and don’t use the stack.

305.10b A player can normally advance up to one Front and retreat from up to one Front during their turn; however, continuous effects may increase these numbers.

305.10c Each Front card has a striated text box and a "Advance" symbol. An advance symbol is a keyword ability that represents a static ability. Any abilities printed within the same text box striation as an advance symbol are part of its static ability. "{Advance} [Abilities]" means "As long as this Front is advanced, it has [abilities] and loses any other abilities not contained in this text box striation, including mana abilities".