In Dominion you choose 10 of the 25 Kingdom cards to play with in a given game, generally at random. Is it possible/advisable to play with less or more sets? I've considered playing with less to make it simpler for new players, and likewise more to add possibilities for players that are already familiar with the card types, but I've never heard of anyone else trying it before. It would throw off the end conditions (one of which is running out of three stacks of Kingdom cards, which is respectively more/less likely in my examples); would it unbalance any other game aspects or lead to problems?
I think playing with less would be fine. From the games I've played with there are about 2-5 stacks that never get any buys, and 1-2 that get bought down really fast. For inexperienced players I think it would be a big plus.
However, for experienced players it could change some of the strategy a bit. The other stacks, even if unbought, can serve as a threat that players may buy those. For example, if there were multiple reaction cards then the attack cards seem less desirable. So right there 2-4 stacks may be off-limits on the premise of mutually assured destruction. However, with no reactions attack cards gain a lot of value.
Thus adding more cards would be bad IMHO for experienced and inexperienced players but for different reasons. The inexperienced players would be too confused while the experienced players would settle on 'sure fire' strategies with so many other strategies to game against. A limited selection limits the amount of competing strategies, and hence may reduce the number of spoilers to more entertaining card selections.
The Black Market promo card may give you some of what you're hoping for. If a Black Market is one of your 10 Kingdom cards, it allows vast diversity in the actual Kingdom cards in the game.
It probably won't break the game to tweak the number of Kingdom cards if that's really what you want to do, but that magic number of 10 was presumably arrived at after a lot of playtesting.
Personally, I find that beginners have an easier time if you play some of the recommended sets or play with the simpler cards (many of the base Dominion cards fill this bill). Another way to cater to beginners is to "draft" the set of Kingdom cards by letting each player select a pile from the 25 in turn. That way each player is familiar with a few piles at least, since they selected them.
For advanced players, drafting the set is also a great way to liven things up because they'll choose cards that synergize well and are generally powerful. The other way I like to enliven the game for advanced players is to increase the card pool by mixing more expansions in. Selecting from the nearly 100 cards in the first 4 sets will basically always give you new combinations that are ripe for experimentation.
Playing with 6 advanced players and 4 or 5 sets worth of cards is quite a cutthroat, enjoyable experience.
I've experimented a bit with different numbers of kingdom cards. For small variations (say 8-12 piles) the game seems mostly unchanged. That said, 10 usually feels like a good number. This depends largely on how you select those cards. With straight-up random selection, with fewer cards you decrease the number of combinations. This can often result in games without much engine potential, so players will just play Big Money, or Big Money + (one or two cards), which doesn't make for a very interesting game. However, if you're picking cards deliberately, you could craft good sets with fewer than 10 cards.
Playing with more than 12 can overwhelm people with choices. In many cases, whether a game ends on piles or on Provinces is determined by what piles are out there. There are some cards that almost always get bought out (e.g. Fishing Village, Caravan). If you use more than 10 Kingdom cards, I think you will find a higher percentage of games have more than 1 very popular card, which might result in more frequent endings on piles. Conversely, if you have fewer than 10 kingdom cards and people start playing strategies close to Big Money, I think the game is more likely to end on Provinces. (I only include this because I think it's opposite to what you assumed in your question.)
As far as house rules to modify the kingdom cards, the most successful one we've tried at my house is to have mixed piles where you can only buy the top card. We'll select 8 or 10 kingdom cards (often with each player secretly picking a share), then shuffle them all together. This stack is divided into 4 piles, with only the top cards visible. On your turn, if you gain a card, you put a token on all the piles you didn't buy from, and when a pile has tokens equal to the number of players they are removed and the top card is placed on the bottom of the pile. We like that you only have partial knowledge of what's going to be available, so there's a lot of excitement when new cards get revealed. It also increases the luck factor, which can help even a game out if there's significant skill gaps between players. We'd do it more often, but it's a bit of a pain to set up and clean up....
This is kind of an indirect answer to the question, but I've played with the following alternate rules (for 2 players only):
Lay out treasure, victory, and curse cards as normal. Optionally lay out a randomly chosen defense card (Moat, Lighthouse, etc.) and a randomly chosen alternate victory card (Garden, Harem, etc.)
Each player writes down five kingdom cards that he would like to play with (A card may be chosen by both player). The lists are swapped and each player can veto one of his opponent's five cards and replace it with any card of the same cost. Lists are returned to their owner and each owner gets his own five private stacks of 5 cards each according to the list.
A player can purchase cards from the communal piles (treasure, victory, curse, and the optional cards), or from his own private five piles, but he cannot purchase from his opponents'.
After the game, players swap their five private piles and play a game with their opponent's chosen cards.
In my group, we tend to adjust the number of piles based on the number of players. With 3-5 players, we keep 10 piles. 6-7 players 11-12 piles.
Keep in mind that, if you have all 5 Dominion box sets (like I do), you have 112 Kingdom cards to choose from, so you may want to mix and match them. 115 if you have the 3 promo card sets as well.
Recently, we've been doing one of the following methods to choose cards:
- Each player chooses 2 cards. If there are not 10 cards yet, discuss what other cards to add as a group.
- Use a randomizer program (Dominion Kingdom Deck for the iPod Touch/iPhone seems to be popular where I work) to select 10 cards. Each player can then opt to swap out 1 card for a card of their choice.
If we have multiple games, we do the second between each game.
For sake of speed we often play with only 10 piles of 8 cards in 3 player games, and 8 piles of 8 cards in 2 player games. Faster games are a bit more exciting and gives new players a few opportunities to get the hang of the game - as well as see more cards as we mix up a few piles in followup games.
While I do like to randomize the sets, I find it's best to always have a few favourites in the mix. I don't have a complete list, but cards like Bridge, Coppersmith, Pawn, Talisman are highly desirable & help burn piles faster.