I recently lost a game of Dominion where my opponent spammed Minion repeatedly. During this he racked up tons of coin while forcing me to discard my hand once per turn. I cannot remember the other cards on the board but during the game I was unable to successfully counter. Besides Moat or Lighthouse what are some good strategies to fight off Minion?
As you have seen, Minion is a powerful card that, unlike many other Dominion cards, "combos" well with itself: if you draw two you can play one for cash and one to get a new hand, possibly getting another Minion, and attacking the opponent as well!
Minion is a card that's difficult to ignore. There are several ways you might consider to handle it:
Like most Dominion questions, it depends on the board, so only general advice is possible.
The first principle is that Minion is simply a very good card — it lets you accumulate money while drawing more cards. The damage the discard does to the opponents is nice, but it’s not that significant. Frequently, the best counter to Minion is going to be getting your own Minions. Evaluating other potential strategies’ speed in relation to Minion is something that requires experience.
The two main approaches to actively countering Minion are to improve your own deck’s robustness in the face of discard attacks, and to slow down your opponent’s deck.
Slowing down their deck is easy — if there are attacks that fill their deck up with junk, use them. Discard attacks don’t help — as long as they have a Minion left in hand, they’re off to the races. For this purpose, Torturer is a discard attack — a Minion deck will pretty much never take a curse.
Making your own deck more robust is a harder subject. Except for cards that get better when your hand is smaller (Library, Menagerie) or that let you usefully react (Tunnel, Horse Traders), it’s not really any different from the art of making your deck good in the first place. If you can build a strong card-drawing engine, the fact that you’re starting from four cards won’t matter much. If you can trash all your junk, four cards should be enough.
The biggest difference is that the marginal cards (particularly those that aren’t +1 card, +1 action) are proportionally weaker. That includes both Moat and Lighthouse, particularly Moat. Yeah, they’re fine if you have them when the opponent Minions, but if you draw them in the four-card hand, they mean you’re unlikely to be able to buy anything great this turn. If you’re playing with four-card hands, the average value of your cards needs to be higher — you can’t get away with cards that aren’t really pulling their weight. Before buying a card, ask yourself if it’s really helping your deck, or if you’re just buying it because you think you want to buy something every turn.
(This is true in every game of Dominion. It’s just more true when your opponent is throwing Minions around all the time.)