i haven’t started hearthstone yet and was thinking of learning to play it. are the expansions paid gateways at certain levels?
Regular expansions (like Mean Streets of Gadgetzan, which just launched) simply add new cards to the available set. You can play as much as you want without those cards, but usually an expansion changes the preferred decks for a lot of players, so if you want to be competitive it helps to have the new and shiny stuff. Sometimes old deck archetypes remain competitive without cards from the latest & greatest expansion, but it really depends on how the ‘meta’ evolves.
Then there are the solo adventures, like The League of Explorers. These are not really gateways, you just get cards you wouldn’t have gotten in other ways. As time moves forward, older expansions get rotated out of the set of cards that can be played in ‘standard’ mode, so you really suffer no ill effect from not having them unless you play in ‘wild’ mode where all cards are allowed.
You can pay for solo adventures with gold, but it takes a while of doing daily quests to save up. 700 gold per wing, times 4 wings per expansion. You can also pay cash, of course; I’m not sure how much they are. To ‘buy in’ to a regular non-solo expansion, you just need to get more card packs, either through cash or at 100 gold a pop.
If you’ve yet to play it, I suggest not worrying about the expansions and whatnot. Just try the free stuff and if you like it, you can always opt in for more.
Now is a good time to start. MSOG expansion came with a set of 3 quests that will net you 6 free packs of the new expansion. You’ll also get some free packs from the “new player” quests, along with enough gold to try out arenas. Arenas are a good way to see new cards, have some fun and get a pack. They cost 150 gold to get in to, so they cost 50 more gold than buying a pack outright. You play until you lose 3 games. If you do well, you can end up making a profit (6+ wins before your 3 losses).
They also switched up the quests a bit, which helps newer players get gold. Quests used to be like “win 3 games as a Hunter” or “Win 5 games as a Priest or Paladin”. The “win” part of that could get frustrating when you’re starting out. A lot of the new quests are like “Play 50 paladin class cards”, which can be done whether you’re winning or losing.
The single player expansions are good content even if you have no use for the cards they unlock (~12 -15 custom battles, with 2 difficulty levels each).
Then there are also 9 class challenges: matches with predefined decks, 1 for each class. They usually have a single gimmick, but again are good authored content.
I think they’re very thin for the money, myself. There are other competing card games (most notably Hex) that have a lot more in the way of singleplayer content for much less money (none, in Hex’s case and I believe things like Duelyst and MtG: Duels also have that stuff free). And Blizzard seems to only intend them as vehicles for the cards given that they’re rotating them out of availability when the cards rotate out of standard.