I tried to analyse Death Carts abilities, and i couldn't avoid some mathematical reflections, as i don't know whether a simulator for Death Cart exists. What do you think?
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+5$ leaves little doubt that this card can shine - but it is very trappy as well. We will first examine four problems you might face if you get too tempted by five bucks:
Death cart doesn't work with money decks
Let's first analyse a simple BM-strategy and assume that we open silver+death cart. We will use it twice to trash our ruins and once to trash itself; apart from that, we play BM. How will this perform?
If you draw your death cart in move 3, you have a chance of 53.8% to draw it with a ruin. Suppose you do so, and in move 3 to 5 you buy a treasure and draw your death card again in move 6. Till then, your deck will have 16 cards, and the chance to draw your second ruin with your death card is roughly 26.7%.
First observation: The probability of never missing your ruins is approximatively 53.8% * 26.7% = 14.4%; thus, in 6 of 7 times you will miss your ruins at least one time.
Another interesting question might be: How long does it take in average till you have trashed both ruins? If we assume for the sake of simplicity that the above probabilities will be constant, you will need 1/0.538 + 1/0.267 = 5.6 shuffles (the true average will be higher, as your deck grows after each shuffle).
Based on this, we can highlight the benefit if you need 6 shuffles to clean out both ruins - which means that you have played your death cart twice and will play it a third and last time after the seventh shuffle. You have paid $4 initially to get three terminal platinums - it would be a great deal without the opportunity costs. The true problem is, that your death cart has taken a slot in your deck 7 times, and your ruins even more (depending on how often you missed both). Obviously, using 14 other cards would be better - by far!
This poor BM-performance might be improved with a more flexible concept of when to trash death-cart, or maybe with a second death cart. But none of these change the principle verdict: Don't use it for a money-based strategy.
Gaining ruins is critical
If you have some +Buy left, you might look at ruins as free fuel for a death cart. This is profitable if you match death cart with the new ruin and no other ruin in the same hand. Unfortunately, this takes a long time in average.
Say, you have 20 cards (without drawing or sifting), containing Survivors and a death cart. If you choose to gain an abandoned market, the probability to match it with your cart without having survivors in the same hand is roughly 0.17, and in average you will need approximatively 6 turns till your death cart trashes your abandoned market. But using 6 slots with a ruin and one more slot for your cart is not worth 5$ at all.
Trashing the ruins is rarely an effective help
Example given, Steward is generally considered as a good trasher. So, one might argue, that if death cart misses the ruins, Steward can trash them. But usually, this is a bad plan, for two reasons: First, the ruins might miss both Steward and Death Cart. And second, even if you trash both with Steward immediately and use your Cart as a one-shot, your opportunity costs are too high: After trashing, your steward hand has 2 cards instead of 6 (if you had chosen +2 cards). Adding the slot your cart uses, you play with 5 cards less to obtain terminal +5$, which is a bad average.
Other trashers imply different opportunity costs, but the baseline remains the same: If trashing the ruins needs a noticeable effort, the one-shot isn't worth it.
Trashing action cards often has little benefits
Say, you want to trash a swindler for $5, which looks like a benefit of $2. Unfortunately, it isn't: Not only you lose your swindler worth 3$, you also can't use it in the actual hand. Summed up, instead of having a 3$-swindler, +2$ and the swindlers attack, you have +5$. This is seldomly a great win.
Death Cart works in a stable engine
Now, let's switch to the situations where DC is great.
The classical one is a stable engine. We don't have to worry about matching with the ruins if we draw our whole deck. With leck of money, death cart can be the star of the show.
Just make sure your engine isn't too vulnerable: If the probability is high, that 3 new cards will interrupt your drawing, they aren't worth it. Additionally, if you have a lack of +actions (and already other strong terminals), beware of adding three more terminals.
Death card is an endgame card
Essentially, DC helps buying provinces - therefore, $5 is best when it comes up late. Let's extend our previous example and say that you have DC, Swindler, and three coppers. You can buy a province with DC, without it, you play the swindlers attack and have a swindler and a 5$ card. The latter combination is more helpful in move 3, but obviously weaker in the last round.
Another reason why DC is stronger if you buy it late is that the ruins hurt less. If you buy it in the next-to-last round, you get +5$ for three cards, which is an average of 1.7. This is fairly good (you need 1.6 to get provinces), but more important, you get all your money on a single card, and accumulating buying power is crucial in the endgame.
A third reason for DC's endgame-power is its synergy with some alt-VP-cards: Three cards are a nice-to-have in a gardens game, and they can be a big boost with vineyards and fairgrounds.
Miscellaneous opportunities
Finally, our tricky card leaves space to many occasional synergies:
- With Trader in hand, you can avoid both ruins and obtain a 5$-one-shot-card, which is very strong in the endgame. With Watchtower, topdeck it with one ruin and trash the second one.
- DC yields big amounts of money very early. This can be effective with Forge on board or with overpaying strategies.
- Like every trasher, it synergizes well with on-trash-abilities, especially with Market Square.
- Inn and Herald help matching your ruins and your cart.
- Rats and Fortresses are useful.
- opponents looters increase the probability to match cart/ruins.
Summary
There are several good occasions - but Death Cart can also be a trappy card in many kingdoms. Just don't overestimate it in the described critical circumstances - those ruins can be a mess!
Synergies
Stable engines
Endgame
Watchtower, Trader
Rats
Fortress
Vineyards, Gardens, Fairgrounds
Forge
Overpaying
Inn, Herald
Oppponents looters
Antisynergy
Money games
