You, along with everyone else at the table, open one pack each and select—"draft"—one card from that pack. Then you pass the rest of the cards to the player on your left. The packs get passed around the table until all the cards are gone. You repeat this process for the second pack, passing to the right.
Players "draft" three Packs which contain 15 cards (10 commons, 3 uncommons, and 1 rare or mythic rare, 1 basic or common land). This means after picking one card the pack is passed on to the next player. This continues until all cards have been picked. The direction for passing the packs alternates with every pack.
Yep! The cards you draft are added to your collection as soon as you draft them, unless the event states that it is a phantom draft, but arena rarely does those.
How to draft: First, players sit around a table in a semi-circle. Each player then opens a booster pack and picks a single card without showing the other players. Each player then passes the remaining cards to the left, and continues drafting from the new cards they get from the player on their right.
Keep in mind that you're not allowed to look at your cards during the drafting process and after everyone is done drafting the first pack, there is a 90 second review period where you get to look at all the cards you've drafted.
Team Draft works best with six players. Before the draft, assign players to two teams and seat players alternating teams. Players draft as they would a Booster Draft. After the draft each player plays each opponent on the opposing team.
The Draft format is a true test of skill. Build decks on the spot from a rotating selection of booster packs. Pick a card and pass it on. Harness the chaos, explore emergent strategies within the cards your opponents pass you, and draft a unique and exciting deck.
To have a Booster Draft, you need three things: 3 Booster packs per player from the current draft format. 8 total players (It's possible to draft with fewer than 8, but 8 is the number needed for sanctioned Magic drafts) A healthy supply of basic lands.
After being seated around a table, each player simultaneously opens one booster pack, selects a single card, and then passes the rest to the next player over. After all players have drafted fifteen cards, they each open their second pack, and drafting continues (sometimes in reverse order during the second pack).