I'd agree with
Embargo being a card that shows the skill of the player.
I think using
Embargo well, and knowing when to take it requires quite a broad skill set, including but not limited to:
- Understanding money density and when a disposable silver is better than a permanent silver, and vice versa.
- Understanding terminal action economy.
- Knowing when to spend more than $2 on a $2 card.
- Understanding pace, and the shuffle timings, thus knowing your odds of getting your embargo down in time.
- Understanding gold advantage, and the benefits of an early gold lockout, and of course how to get two gold and an embargo down before your opponent does...
- Understanding marginal VP counting, and the difference that one curse can make.
- Understanding the key strategies and combos, so you can block or slow your opponents emergent strategies.
- Understanding how to use the curse pile to approach a three pile ending.
Many of the games I've been most proud of have including opening Embargo with a 4/3 split, and its definitely my favourite Dominion card, mostly because of its ability to alter the dynamic of a game subtly. I've also seen it used horrendously badly - many mid level players seem to use it to block what they see as a dominant strategy rather than the strategy that is clearly being pursued by their opponents, or blindly embargo something someone has bought once. For example, in a recent game, an opponent got a Witch/Embargo on a 5/2 opening (to my 4/3) and what did he Embargo? Not the Witches, which was the obvious solution, but the Fishing Villages... which I already had one of, along with an embargo. Needless to say, I won that game, which pleased me greatly as coming up from the wrong end of a 5/2 opening with a strong attack present is always hard...
Worst of all, the lowest level players often embargo cards that they think no-one will ever want to buy, like the curse pile, In my opinion, the only time you should embargo the curse pile is if you want to buy a curse and gain a curse, and thus bring about a three-pile with you in first place.
So for me, Embargo is the card that most differentiates skill levels between players. Sure, the multiple choice cards do that too (Governor especially), but how to use those cards is easily taught on a card by card basis, whereas I believe mastering Embargo requires mastery of the whole game.