Rebuild is a powerful card. Some powerful cards make games stretch on, almost interminably, like Goons and Mountebank. Others, like Tournament or Wharf, can make a game go by in a few minutes. Rebuild is one of the latter.
So what does Rebuild do? Like Rats (which I wrote my previous article on) and most other Dark Ages cards, the point of the card is not immediately apparent from its wording. Rebuild essentially upgrades your Victory cards, as long as they are in your deck. Generally, this means going from Estate to Duchy to Province (and sometimes Colony). This process, like that of Rats, tends to be very quick, and a player who can get a couple Rebuilds going before the other will have a marked advantage, barring other game-changing cards.
When should I buy Rebuild? As soon as possible, and you should probably get two. Since Rebuild gives +1 Action, there's no need to fear terminal collision. I like to break cards into two groups: those you should get early, and those you can wait to get. The former group includes Rebuild, along with Mine, Goons, Monument, and most Attack cards - cards whose effect you want as often as possible for as long as possible.
Okay, I've got a Rebuild (or two) in my deck - now what? Rebuild's wording allows you to name a card that you don't want to see trashed, and then Rebuild will hunt through your deck for a Victory card that is not that. In most situations, you'll want to name Province, as you want to upgrade your Estates and Duchies, as doing so will increase your point total. But, like with the Remodel trick, trashing a Province to gain another Province can be quite effective in emptying the pile if you already have a significant lead - in those cases, simply name Estate, to ensure that your Duchies and Provinces are the ones getting trashed, thus emptying the Province pile.
Remember that you only start (normally) with three Victory cards in your deck - if you Rebuild them fully, you'll only have three Provinces. Therefore, you need to help your Rebuild out by throwing a couple Duchies (or, if you're having trouble fielding $5, Estates) its way. Just one or two can help you get the better end of the Province split.
Also note that Rebuild will discard your Actions and Treasures, so don't develop an attachment to them. Just think of it as express cycling. In fact, Rebuild's nature means that you won't need as many Treasures. Most decks are oriented around the need to field $8 (or $11) every turn in order to get Provinces (or Colonies). You'll be getting Provinces through your Rebuilds, so, like a Duke deck, your deck should be oriented to field $5, so you can pick up Rebuilds and Duchies.
Is there anything else I can do to help my Rebuild? You can use Rebuild as a supplement to an engine, or you can make Rebuild the centerpiece of your strategy. For the latter, remember that your two objectives are: 1) Play Rebuild as often as possible, and 2) Throw extra Victory cards into the mix. So you want to look for cards that will help you do that. To further objective 1, look for sifting cards, particularly non-terminal ones, such as Cellar and Warehouse. Sage is moderately useful, but will get caught on Duchies and Provinces too often in the mid/late game. Rebuild is a great target for Throne Room and King's Court. But the very best way to play Rebuild as often as possible is to just buy lots of Rebuilds, which is what you should be doing with your $5 hands when the Duchies run out (and they will run out). For objective 2, look for cards that either specifically gain Victory cards, like Followers or Count, cards that gain cards of any type, like Workshop or Armory, or cheaper cards that field enough coin to procure Duchies, such as Horse Traders. Cards like Mandarin are too expensive, as you want to focus your $5 buys on Rebuild and then Duchies. Count, on the other hand, works very well with Rebuild because it has the awesome power to just straight up gain Duchies. You'll be getting your $5 investment back in spades if you pick up a Count on a Rebuild board.
If you elect to have Rebuild complement your engine, be mindful of the order in which you play your cards. In general, you'll want to play Rebuild first, as cantrips and drawers will bring your Victory cards into your hand, where you don't want them to be. Sifters, on the other hand, should be played first, as they will let you discard those Victory cards. Embassy is the best of both worlds here, but at $5, it's interfering with your Rebuild and Duchy buys.
When should I not go for a Rebuild strategy? When a more powerful strategy is available, which will be rarely. An Attack that should give you pause with a Rebuild strategy should be Saboteur, which can undo your Rebuilding, or worse, destroy your Rebuilds, but most players ignore that card often enough for you to not worry too much about it. While Rebuild is fast, there are some faster strategies out there. A well-made engine that can buy Provinces outright will outstrip a Rebuilder that has to trash precious Victory points. Mountebank can fill your deck with enough junk to prevent you from seeing your Rebuilds, and you should never ignore it in favor of getting the early Rebuild. A competent Goons player can easily outstrip a Rebuilder; while the discard Attack should not concern the Rebuilder, a Goons player will not be helping the Rebuilder empty the Provinces, and a good Goons player will be able to accrue enough points to be guaranteed a win against a player using Victory cards alone. Now this is not to say that you should ignore Rebuild in these cases; you should instead shift focus to the more powerful card, but feel free to pick up a Rebuild as a supplement.
My opponent is Rebuilding like crazy - what do I do? Well, typically the best thing to do is mirror the Rebuild, and hope you can get a few more Duchies into your deck than your opponent. If, for some reason, you don't want to do that, there are a couple things you can do. Attacks are conventionally the easiest way to slow a player down, but Cursing/Looting will do little against a Rebuilder, except possibly make his Rebuilding less frequent. Discard or Top-decking Attacks will usually help the Rebuilder (see below), so don't try those. To counter a Rebuilder, you have to keep in mind how the Rebuilding goes down. Rebuild works stepwise - Estate to Duchy to Province. If you remove a step by emptying the Duchy pile, suddenly Rebuild is neutered. Also realize that a Rebuilder is not gaining as many points as a player buying Victory cards outright - Rebuilding a Duchy into a Province only gains you 3 points. Those other points are being thrown into the trash pile, where a Graverobber can handily nick them. Now, Graverobbing the leavings of a Rebuilder may not be enough; the best way to knock one down is in the literal fashion: with Saboteur or Knights. Rogue would simply be a Graverobber here, as its Attack only activates when there's nothing in the trash to find. If the trash is full of Duchies, you won't be Attacking your opponent. Only the first few turns will you be able to - the point when they're turning Estates into Duchies. Saboteur is probably the best Attack to use against Rebuild. Why? Saboteur has no upper limit, so it can hit Provinces. Saboteur is doing exactly the opposite of what a Rebuilder is trying to do - downgrading cards. And a Rebuilder's deck is going to be full of Rebuilds and Victory cards - perfect targets for the typically mediocre Saboteur. This will be most potent when the Duchy pile has run out, making Provinces drop 5 points down to an Estate, or 6 points to a non-Victory card; one such play can win you the game. As such, Saboteur should be a mid-game buy - you'll want to get your own Rebuilds first while helping to empty the Duchy pile. Now, you won't want to just pursue Saboteur - even here, you should be trying to Rebuild yourself, but that Saboteur can spell the difference between victory and defeat. And if you can hit your opponent's Rebuilds, they are now dead in the water without a strategy. Knights can also be helpful here, but they cannot hit Provinces, and can't go hunting like Saboteur can, so they may just uselessly discard Coppers. Now be mindful that you need to be a fairly skilled player to pull off Sabotaging a Rebuilder - a novice player would most likely have too much trouble creating an economy while going for Saboteur, which is death when the other player really doesn't need to add to their economy. The other options are to either fill the Rebuilder's deck with junk quickly enough with either Mountebank or Cultist that they can't find their Rebuilds often enough, or to pursue a Victory token strategy, typically with Goons, that can amass enough points to have no need of Provinces.
To review:1) Rebuild is a very fast card that can dominate boards.
2) In general, name Province.
3) If going for a pure Rebuild strategy, only spend $5 on Rebuilds and Duchies.
4) A skilled player can use Saboteur to counter a Rebuilder.
Now let's discuss specific interactions with other cards. Bear in mind that if you're going for a pure Rebuild strategy, any card costing $5 will get in the way of you buying Rebuilds and Duchies, and should most likely be ignored.
Shelters: According to Donald X, Rebuild was the last card to be added to the Dark Ages set, and, like Ironmonger, seems oddly ill-fitted to the expansion, as both cards suffer when Shelters are used. Using Shelters replaces your starting Estates, leaving your starting deck with a single Victory card in it, and Overgrown Estate only costs $1 - that's not enough to Rebuild it into a Duchy - thus you have to make an extra step on your way to Provinces (or, happenstance forbid, Colonies). This is not to say that you should ignore Rebuild in a Shelters game - just be mindful that you'll need to buy a few more Duchies (or Estates) to make it worthwhile.
Colonies: Rebuild, unlike most other cards, takes neither a boost nor a slump when Colonies are used. True, it now requires an extra play of Rebuild to get your Victory cards to their highest potential, but Colony games tend to be longer anyway. Rebuild can even be helpful in Colony games, as you need not outfit your deck with the necessary funds to procure Colonies - just Rebuild up to that. Be aware, however, that although Provinces are now a stepping stone up to Colonies, they still count as an ending condition when they're all gone, so be mindful of the size of the pile.
Kingdom Victory cards: Rebuild is certainly a convenient way to acquire alternate Victory cards, but don't look to it as a means to beef up their point totals. Since Rebuild essentially replaces cards, most of the variable point Victory cards will not get any mileage out of Rebuild. Better to just buy them outright, particularly Silk Road, which would prefer to keep your starting Estates.
So does Rebuild actually combo with any kingdom Victory card? Yes, actually.
Tunnel: Just name Tunnel. Your Estates will turn into Tunnels, and then you'll be swimming in Gold as the Tunnels just fly by.
Feodum: Unlike the other counting kingdom Victory cards, Feodum's point total will actually increase with Rebuild - when you trash a Feodum, you get three Silvers, increasing every Feodum you have by one Victory point. Just remember to at least hang on to some Feoda.
Duke: Name Duchy or Duke every time. Your Estates will turn into Duchies, allowing you to focus your $5 buys on Dukes, whose pile will quickly empty as your Rebuild finds them. Or let them turn into Dukes, and buy Duchies. Either way. Just be mindful of that emptying, or you'll start to lose Dukes and/or Duchies. Remember - you don't have to play a card in your hand.
Other standout interactions:Baron: Rebuild takes away your Estates, so Baron can't make money for you (sad face), but then Baron gives you more Estates, which you can turn into Duchies (happy face).
Tournament/Explorer: Rebuild can help you get to those precious Provinces more quickly, allowing you to get the full potential out of these cards. Once you've Rebuilt an Estate into a Duchy, make sure to name Estate to ensure your next Rebuild will hit that Duchy.
Trade Route: Don't you hate that niggling desire to buy an Estate to make your Trade Routes better? Rebuild helps you get around that by quickly getting the token off of Duchies, and usually Provinces as well.
Rebuild as a defense: Rebuild can be an excellent way to counter a lot of Attacks. Any Attack that forces you to place cards on top of your deck can be countered by putting Victory cards there for Rebuild to hit. And Spying Attacks that like to leave Victory cards on top are very effectively neutered by Rebuild. And while Wandering Minstrel and Farming Village snag on Ruins, and Scrying Pool snags on Curses, Rebuild discards them all (along with everything else).
Does well with:
Duke/Feodum/Tunnel
All that stuff I mentioned
Does badly with:
Scout
Most alternate Victory cards
Counter with:
Saboteur
Mountebank/Cultist
Victory token cards
