How Many Decks? Part 3: Unlimited Reinforcements
Now updated with the newer reinforcements
Welcome to the third installment in this series that tries to count the number of distinct decks we can build in Summoner Wars. In the previous parts we examined the number of combinations of Champions, and of Commons from a faction’s starting deck. Now we’ll add in the Reinforcements! (Including the new ones about to appear.)
Same Principles, Larger Numbers
If we count the number of all legal Tundra Orc decks using both the Starter Set and the Reinforcement Pack (and not using any Mercenaries), we already have all the mathematical tools at hand. In Part 1 we saw that the number of ways to choose K objects out of N choices is
C( N, K ) = N! / (N-K!)K!
So we plug in the numbers to choose 3 Champions out of 6 possibilities and get C( 6, 3 ) = 6*5*4 / 3*2*1 = 20.
C( K+(N-1), N-1 )
Just as before, K=14, since we need 18 Common Units and 4 are mandated in the setup. But now with the Reinforcements, N=5, not 3. So, to start with, we have
C( 14+(5-1), 5-1 ) = C( 18, 4 ) = 18*17*16*15 / 4*3*2*1 = 3060
possible combinations of Commons, instead of 120.
But now we need to subtract the illegal combinations, that is those that have more than 10 copies of any kind of Common. To see the number of decks with too many Thwarters, we pick 11 Thwarters and see how many ways there are of filling the remaining 3 slots:
C( 3+(5-1), 5-1 ) = C( 7, 4 ) = 7*6*5*4 / 4*3*2*1 = 35
C( 4+(5-1), 5-1 ) = C( 8, 4 ) = 8*7*6*5 / 4*3*2*1 = 70
We have 2 Fighters in the setup so we have 5 slots free to fill:
C( 5+(5-1), 5-1 ) = C( 9, 4 ) = 9*8*7*6 / 4*3*2*1 = 126
So the total number of legal combinations of Tundra Orc Commons is
3060 – 126 – 70 – 70 – 35 – 35 = 2724
And multiplying that times the number of Champion combinations yields
20 * 2724 = 54,480
That’s a lot of possible decks, isn’t it? (And we’re not even including Mercenaries yet!)
Doing similar calculations for all the factions, we get:
Faction Champ Comb Common Comb Total Comb Tundra Orcs 20 2724 54480 Phoenix Elves 20 2724 54480 Cave Goblins 20 1690 33800 Guild Dwarves 20 2175 43500 Vanguard 20 2154 43080 Fallen Kingdom 4 10956 43824 Jungle Elves 4 8197 32788 Cloaks 20 2175 43500 Benders 20 2703 54060 Sand Goblins 20 2175 43500 Deep Dwarves 20 2154 43080 Shadow Elves 20 1690 33800 Mountain Vargath 20 2724 54480 Swamp Orcs 20 3348 66960 Total 645332
Some trends are apparent. The factions with more Common units on the battlefield at the start of the game have fewer possible decks to build — which makes sense — compare the Swamp Orcs who start with 3, with the Phoenix Elves who start with 4, the Guild Dwarves with 5, and the Cave Goblins with 6. Also note that the two factions with only 1 Champion in their Reinforcement Packs — the Fallen Kingdom and the Jungle Elves — have many fewer Champion combinations, but the extra kind of Common unit increases the number of Common combinations to almost make up for it.
You may have also noticed that two factions are missing in the list above: the Filth and Mercenaries, who have their own unique issues. The Mercenaries by themselves are not that problematical, they just have many more units than other factions, so we have time to discuss them here.
What about the Mercenaries?
There have been 18 Mercenary Champions published — 3 with the Merc Faction Deck, 11 with the Reinforcement Packs, and 4 promo cards — so the number of ways of choosing 3 of them is:
C( 18, 3 ) = 18*17*16 / 3*2*1 = 816
That's a lot more than 20, isn't it? Trippling the number of Champions had a much bigger effect than we might have expected. But we're only getting started: the Commons will show how very fast the factorial nature of combinations goes up.
We have 13 kinds of Commons, 3 in the Faction Deck and 10 from the Reinforcement Packs. The Rallul starting setup uses 4 Commons, leaving 14 slots free, so
C( 14+(13-1), 13-1 ) = C( 26, 12 )
= 26*25*24*23*22*21*20*19*18*17*16*15 / 12*11*10*9*8*7*6*5*4*3*2*1
= 9,657,700
is the number of raw Common combinations, but first we subtract the illegal ones. There are 2 Stone Golems in the setup, so adding 9 more leaves 5 slots:
C( 5+(13-1), 13-1 ) = C( 17, 12 ) = C( 17, 5 ) = 17*16*15*14*13 / 5*4*3*2*1 = 6188
There is 1 each of Rune Mages and Apprentice Mages, leaving 4 slots after adding 10 more:
C( 4+(13-1), 13-1 ) = C( 16, 12 ) = C( 16, 4 ) = 16*15*14*13 / 4*3*2*1 = 1820
All the 10 other kinds of Merc Commons are not in the setup, so we use up 11 slots for them, leaving 3:
C( 3+(13-1), 13-1 ) = C( 15, 12 ) = C( 15, 3 ) = 15*14*13 / 3*2*1 = 455
Giving us the actual Common combinations as
9,657,700 - 6188 - (2*1820) – (10*455) = 9,643,322
We multiply the Champion and Common results for a grand total of
816 * 9,643,322 = 7,868,950,752
There are close to 8 billion different Mercenary decks we can build. The mind just boggles.