I would have put this in the Articles subforum, but
this thread, which is one of my favorite threads on the forum in recent memory, was posted here, so Imitation Is The Sincerest Form Of Flattery (IITSFOF)...
The purpose of this thread is to highlight neat little interactions or synergies between two cards that may not be the most obvious thing. A couple of times this has caught me by surprise in a game and while they may have been talked about in bits and pieces on the forums, I really like the idea of being able to read a thread full of one-line cute tricks. Who knows if you'll find any goodies that you hadn't really thought of?
EDIT: Let's try to keep this thread on topic, please ![Smiley :)](http://forum.dominionstrategy.com/Smileys/default/smiley.gif)
I'll begin:
Quarry and Stonemason: When playing Quarry, the price of Stonemason reduces to zero, so the normal "quarry gives +$2 if you're buying one action" and "you need $2 extra to get the extra action with Stonemason" becomes much better. You get cost reduction on both the Stonemason you buy AND on the overpay!
Apothecary and Shanty Town: Any top-deck interaction will help you trigger your Shanty Towns more, this is true; but I think Apothecary stands to benefit the most from this, as it can get a lot out of using Shanty Towns early to draw your green and pushing your terminals off until later in the turn when you've got the actions to play them and trigger future Shanty Towns.
Doctor and Fool's Gold: These two have a troubled relationship, that's for sure. Fool's Gold is a card that can provide you high-income hands very early, which can lead to very beneficial Doctor overpays if you're paying close attention.
Highway and Horn of Plenty: You don't need to worry about having enough unique cards with Highway around, every Highway you play effectively counts as a unique card since it reduces the cost of whatever you're going to gain.
...and some of the more standard ones:
Highway and Ironworks Cost-reducers and gainers synergize, for sure, but these two probably deserve a special mention. Highway and Ironworks are both non-terminal so it's very easy to get lots of them to increase your chances of collision, and spamming these cards can be a way to get lots of power-$5 cards very quickly.