The Main Phase (メインフェイズ, Meinfeizu) is a term used in Genso Suikoden Card Stories. It is the very first phase of a player's turn.
In the Main Phase, the player has three options.
The player can discard any number of cards from your hand, once only. You can choose to replenish your hand by immediately jumping to your Replenishment Phase. In general, you will almost always want to keep Leader cards in your hand and dispose of superfluous Mission or Facilities cards.
The player can play a new Mission or Facilities card and begin a new battle. The player who plays the card begins the battle. A new Mission or Facilities card cannot be played if there are 2 unresolved Mission or Facilities cards in play by the player already. No more than 4 unresolved Mission or Facilities cards can be in play (2 per player). Selecting this moves the game to the Deployment Step.
If a Mission or Facilities card has been unresolved due to a lack of cards or a card effect prematurely ending an engagement, the player can select an unresolved card and continue a battle. The player who selects the card begins the battle by playing a Character card. Ensuring that you can mostly likely win the card with your current hard is a key part of the game, in order to avoiding wasting valuable manpower.
Selecting this moves the game to the Deployment Step.
Following the Main Phase
Once the Main Phase (and the battle steps within in) ends, the game moves onto the Replenishment Phase.