You can select one Action or Territory Card to play. When you play a card, put it face-up in your play area. We call the place where you put the cards you’ve played the Field. When you play a card, effects written on the card’s ability space activate, in order from top to bottom. (For example, if you play a Farming Village card, you get 1 Coin.) Once you’ve resolved all of its effects, you are done playing the card.
If you play a linkable card (one that has the link symbol arrow on the right or bottom) you can play yet another card from your hand. If the next card you play is a linkable, you can play yet another card after that. If a card has two link symbols, you can then play two additional cards, but regardless each link symbol only lets you play one additional card.
You can keep playing cards like this until you run out of either linkable cards or cards in your hand. If you can’t play any more cards, or you choose not to, declare that your Main Phase is done.
Example: You have 2 Farming Villages, 2 Infantry Battalions, and 1 Apprentice Maid in your hand. You start by playing a Farming Village. The Farming Village’s ability gives you 1 Coin. Since the Farming Village card has a link symbol on the right, you can play another card from your hand. You then play another Farming Village, and then an Infantry Battalion. Since the Infantry Battalion does not have a link symbol, you cannot play another card after it. Also, since the Apprentice Maid is not an Action or Territory card, you cannot play it now.
Example: You have 2 Farming Villages, 2 Infantry Battalions, and 1 Apprentice Maid in your hand. Since the Infantry Battalion isn’t linkable, you can only play one of these at a time, but you have a Post Horse card you’ve kept on your City cards, and it has 2 link symbols on it. This means you can recall the Post Horse cards to your hand, and play it and then the two Infantry Battalion cards.