Your sideboard is one of the most important parts of your competitive MTG deck. In best-of-three matches, games two and three are often decided by who sideboarded better. A well-built sideboard can turn bad matchups into favorable ones.

What Is a Sideboard?

A sideboard is a set of exactly 15 cards that you can swap into your deck between games in a match. After game one, both players can exchange any number of cards between their main deck and sideboard, as long as the sideboard stays at 15 and the main deck stays at its original count (usually 60).

Sideboard Strategies

Hate Cards

Hate cards directly counter specific strategies. Examples: Rest in Peace against graveyard decks, Stony Silence against artifact decks, Blood Moon against greedy mana bases. These are your most impactful sideboard slots.

Silver Bullets

Silver bullets are narrow but devastating answers to specific threats. Pithing Needle naming a problematic planeswalker, Relic of Progenitus against a single graveyard deck, or Celestial Purge against black/red aggro. Use 1-2 copies for matchups you expect occasionally.

Transformational Sideboarding

Some decks can transform their entire game plan post-board. A combo deck might sideboard into a control plan when opponents bring in combo hate, or an aggro deck might bring in a planeswalker package to go over the top. This advanced strategy punishes opponents for sideboarding too narrowly.

Building Your Sideboard: Step by Step

  1. Identify your worst matchups — What decks consistently beat you in game one?
  2. Find targeted answers — What cards directly address those strategies?
  3. Plan your swaps — For each matchup, know what comes in and what comes out
  4. Don't over-sideboard — Bringing in 8+ cards risks diluting your main gameplan
  5. Test and adjust — Sideboard plans need refinement through practice

Format-Specific Tips

Common Mistakes

Ready to build your deck? Use our Hypergeometric Calculator to compute the odds of drawing your sideboard cards, optimize your land base with the Mana Base Calculator, and check out our top competitive decks for proven sideboard plans. Browse all our strategy guides for more tips.