An opening consists of the cards purchased in the first two turns. The starting deck of each player consists of 7 Coppers and 3 Estates or Shelters. Therefore, under ordinary circumstances, if your first hand has 4 Coppers, your second hand will have 3 Coppers, and vice versa. This is called a / or / split, respectively. A / (or /) split means you have a first hand of 5 Coppers and second hand of 2 Coppers (and vice versa). In an ordinary kingdom, players receive / or / splits 16.67% of the time.
An opener is a card that a player buys on his first or second turn. Some cards are better openers than others. Trashers and cursers tend to be good openers, and opening with a Silver or a terminal Silver is also usually a good idea in order to build up buying power early. Some cards, like Moneylender, Coppersmith, or Baron, are usually either bought as an opener or not at all, due to their interactions with cards in the starting deck. Usually, Villages are poor openers because there are no terminal actions in your deck at first.
 Unusual openings
If Baker, from Guilds, is in the supply, players begin the game with an extra Coin token, allowing openings of /, /, or / if the Coin token is spent immediately. Borrow gives a similar effect, by letting you "steal" a card from your next turn for + now. Events in general, particularly in combination with the cards listed below, can produce many weird and varied openings. -costing cards also mess with opening strategy.
Some cards with on-buy or on-gain effects can also alter the usual / or / split when bought on the first turn:
- Noble Brigand: When bought by your opponents on their first turn makes you discard the top two cards from your deck, resulting in various possible unusual openings.
- Nomad Camp: Goes on the top of your deck, which can result in a Nomad Camp/ or Nomad Camp/ split.
- Inn: Can be shuffled into your deck and if so will likely be drawn next turn, giving you a / split.
- Mandarin: Puts the five Coppers you played back on top of your deck, giving you another turn before you reshuffle, turning a / opening into a // opening.
- Stonemason: Allows you to gain two extra cards if you overpay when you buy it, meaning you can gain more than the usual one card per opening turn.
- Doctor: Allows you to trash or discard cards from the top of your deck on-buy; so buying it on your first turn with or more can change the makeup of your second turn in various ways depending on what is trashed.
- Messenger: Gives each player an effective extra to their opening per player that opens with it, with the caveat that they may not get to choose which card they get, and it may miss their reshuffle.
- Lost City: If another player opens with it, causing you to draw a card, it can completely change your output on your opening turns.
- Villa: Lets you pick up an additional or with it, depending on your split.
- Forum: If you open /, you can pick up a card with Forum.
- Guardian: If you gain Guardian in your first turn, you can spend an additional in your second turn, which turns a / opening effectively to /.
With Baker, Lost City, Borrow and Pooka (which comes with the Cursed Gold Heirloom) in a game, it's possible to field on an opening turn.
 Examples of strong openers
- Strong cursers and junkers:
- Pseudo- and real Trashers
 Examples of strong openings
- Mountebank / Chapel
- Tournament / Ambassador
- Governor / Chapel
- Mint / Fool's Gold
- Tournament / Chapel
- Witch / Chapel
- Caravan / Ambassador
- Tournament / Masquerade
- Wharf / Fool's Gold
- Witch / Fool's Gold
- Upgrade / Chapel
- Vault / Chapel
- Hunting Party / Chapel
- Trading Post / Haven
- Minion / Chapel
- Witch / Crossroads
- Mountebank / Hamlet
- Laboratory / Chapel
- Mountebank / Native Village
- Mountebank / Haven
- Only three openings were /.
- Most / openings were Curser/Trasher or Booster/Trasher.