One of the most unique ways to play Magic: The Gathering is its Alchemy format. This format is exclusive to Magic's online client Magic Arena and features online-only cards with unique effects not seen anywhere else.
Building an Alchemy deck is much the same as building a Standard deck, and in fact all the cards legal in Standard are also legal in Alchemy. However, Alchemy has access to digital-exclusive cards and mechanics, as well as rebalanced Standard cards, making the card pool ultimately bigger and more rapidly evolving. While this may not seem like a big difference, these cards hugely affect how the game is played out.
7 Playing Alchemy Like Standard
Alchemy uses largely the same cards as Standard, but Standard decks and Alchemy decks should remain separate. While decks can rhyme, they should not be replicated one-for-one.
Alchemy's digital-exclusive cards are simply more powerful. They are what define the format after all. Additionally, many Standard staples are rebalanced when brought to Alchemy, often altering how they play fundamentally. You should never play a Standard deck in Alchemy hoping to be on equal terms.
6 Not Building Around A Strategy
With digital-exclusive cards, many strategies become very viable, arguably more so than in Standard at times. It can be tempting to throw in every powerful card there is to try to make a powerful "Goodstuff" deck, but often that only leads to wasted wild cards and disappointment.
Finding a more cohesive strategy that has a focused win condition is the more effective choice. If you are building a combo deck in Alchemy, you should be playing cards that get your combo components and protect them. Find a strategy you like and optimize it, using Alchemy cards to refine how it plays until it is formidable.
5 Preparing For Every Deck Matchup
A common mistake in many formats is trying to counter every strategy your opponent comes up with. In most contexts, you have one game to win. Packing your deck with solutions to every meta deck is only going to guarantee that you won't have the correct cards to implement your own win condition.
Even control decks should not be built to counter everything. Your goal is to stall until you can either win or wipe the board. Alchemy is especially difficult to plan for given the amount of random mechanics available to players. It is simply a fruitless endeavor to prepare for every contingency. Build your deck's strategy and stick to it.
4 Not Setting Your Deck Up To Win The First Game
As an online-only format played in Arena, there isn't really a need for a sideboard (except in certain decks) as Alchemy is more frequently played in a one-game format.
Therefore, you should only have your best cards in your deck and treat it as if it is immutable, because it often is. While some games are played to best of three, this is by far the more uncommon way to play, and should not be a concern for most Alchemy players.
3 Not Optimizing Your Deck To Save On Wildcards
Alchemy is only playable on Magic Arena, meaning that the economy to get Alchemy cards is much different than any other format. To get cards, you have to either buy online Alchemy packs, or craft cards with wildcards.
Wildcards are difficult to obtain, and are often the limiting factor in what cards you can get. This can lead some decks to suffer as they play suboptimized version, or not enough, of their key cards to save a few wildcards.
If you are in need of wildcards, always get the commons and uncommons first, then work your way up to rares and mythics. Gold packs (which have Alchemy variants) are the best way to get rares and mythics, ensuring the most efficient use of your limited gold. Either way, careful planning of what decks you want is essential to making a quality Alchemy deck without breaking the bank.
2 Not Knowing What Standard Cards Have Changed
Alchemy is also host to rebalanced Standard cards. These are often nerfs (rarely buffs) to popular Standard staples meant to bring out more diversity between the two formats. These can be immensely tricky to find in the Arena client and will force you to actively seek out the cards, or find a site that catalogs the changes.
Nothing is worse than relying on a bomb, only to find out that it no longer functions the same in Alchemy. Knowing what has changed is the only way to combat this beforehand.
1 Underestimating That Luck Has A Lot To Do With Winning
Perhaps more so than any other format in Magic, luck plays a huge part in Alchemy. Most of the digital-only cards have exclusive keywords like seek and draft which are all random effects that find or create random cards. While often powerful, these can easily be duds depending on the outcome. Many of the steal effects in Alchemy also use this random chance.
You could get a key land drop or game-winning powerhouse, or you could get a useless card that doesn't even work with your deck. All in all, luck plays heavily on Alchemy and is a big factor in getting the most out of your cards. If you do not like that, then you should play cards that do not lean on these random effects, but at least recognize that your opponents will be using these cards to luck into some big plays that could win them the game.