Combo: Trader and Feodum
|Trader / Feodum|
|Set(s)||Hinterlands / Dark Ages|
In general, Trader is a fairly mediocre card. Getting a pile of Silvers is nice, but usually not at the cost of a single expensive card. But with Feodum, you'd much rather have the Silvers. In most kingdoms that feature these 2 cards, the play will be something like the following:
 Purchases (in order)
- Buy one Trader
- Buy as many Feoda as possible (get Silver if you only have , pass on or less)
When Feodum pile is empty...
- + = buy Province
- - = buy Trader (or Duchy if the game will end before you get another reshuffle)
- Less than = Silver or Estate
 Using Trader
Use Trader on the following (in order of best trade to least):
- Province (see math below)
- Feodum (see math below - in a few cases, you wouldn't, but usually, yes... especially early in the game)
- Rats quickly turns your Coppers and Estates into cards that can be turned into four Silvers each, as well as drawing you a card. This is the only instance where Rats does well with Trader.
- Fortress can also be useful, as it can be trashed over and over again into Silvers, as well as letting you play more than one Trader per turn.
 Math: Trader on Feodum
When do you want trade a Feodum for 7 Silvers? The mathematical answer is... often!
The formula for the calculation is:
And here is a cross-table of that formula. The left side shows how many Feoda are in your deck, the top is how many Silvers. Red values show when it isn't worth it (VP-wise) to trade in your Feodum.
Bear in mind that this chart only takes into account the VP differential. If there is still a reshuffle or two left before the end of the game, the 7 silvers also provide buying potential. An immediate -1 or -2 VPs could be compensated with a higher probability of making a Province purchase in your reshuffle.
 Math: Trader on Province
The math for understanding when to use Trader on a Province is much simpler:
- If you have 3 or more Feoda in your deck, DO IT. Adding 8 silvers will always give you at least 6 VPs, and therefore is worth it.
- If you have only 1 Feodum, DON'T DO IT. Trading a Province will leave you with only 2-3 VPs, a net of -3 or -4.
- The situation-dependent case is 2 Feoda. 2/3 the time you will receive 6 VPs (net = 0 VPs) and 1/3 of the time 4 VPs (net = -2 VPs). Thus, on the last turn of the game, don't do it. But if you have a reshuffle left, you probably want the buying power of 8 Silvers.
 Math: Trader on Colony
How did you get Colonies in your deck playing Trader/Feodum? Huh, well, here's the math:
- 4 or more Feoda: DO IT
- 1 or 2 Feoda: DON'T DO IT
- 3 Feoda: 2/3 of the time you gain 12 (net +2 VPs), 1/3 of the time you gain 9 (net -1 VPs)