Starter Guide

Thank you for your interest in BOS! In case you didn’t see it on the home page, BOS is the first luckless trading card game. This means no shuffling your cards, no drawing cards, and no dice rolls or coin flips. There are many things about BOS that make it unique, even though the unique things will appear to be very similar to things from other trading card games. If you have played another trading card game before, it is a good idea to think of BOS as a completely new game, and not use any biases from other similar games while you read these rules.

General Rules

Starting Info

At the beginning of the game, you have one deck of 24 cards. It consists of 3 wizards, 10 summons, 10 spells, and 1 boss, all of which will share the same color (either red, yellow, or blue). You can only have up to 3 copies of the same card in your deck, and you must have 3 different wizards. If you have a starter deck, this is pre-made for you.

When you begin the game, you will set up your cards in various spots. Your summons are stored in a face-down pile called the castle, and your spells are stored in a face-down pile called the spellbook. Both your castle and spellbook can be kept anywhere comfortable, as long as all players can see them. You will also need one more face-up pile for all the cards you are finished using in game, which called your graveyard. Finally, you’ll set up your wizards and boss face-down on the battlefield, based on the description later in the guide.

Any cards that have been face-down for the entire game are private, and can only be viewed by the player who owns them. You can look in any pile you own, or any cards that are public, at any time. For example, you can look in your castle and spellbook, but not an opponent’s. You can also look at an opponent’s wizards once they have been flipped face-up for the first time, and you can look at any player’s graveyard at any time.

You begin the game with 30 life. Bring your opponent’s life down to 0 to win! You also begin the game with 1 vim, which is used to play certain cards. Determine who goes first with a luckless method, whether that be Rock Paper Scissors or the competitive “bidding game” described later in the guide. Remember: No luck in BOS!


Every card shares the same layout, with 6 spots that are universal across all card types.

  1. The top of the card is the name of the card. Every card with the same name will have the same text on it.
  2. In the top left circle, there is an icon to represent the type of card.
  3. In the top right circle is the color stone, showing what color the card is.
  4. In the box at the bottom is the ability of the card. Abilities tell you what the card does, and can be used to swing the game in your favor.
  5. Finally, the bottom two boxes give you info on the card’s production. The left box has the artist, and the right box has the production edition and rarity. Many thanks to BOS’ wonderful artists! 😀

Certain card types have extra spots for more information, which will be elaborated on later in the guide.

Forest Sage: Yellow Wizard

(Wand icon)

Essence of Nature: Yellow Summon

(Summoning circle and hand icon)

Pyro-Maniac: Red Boss

(Evil horns icon)

Perfect Infusion: Blue Spell

(Magic swirl icon)

Battlefield Setup

Your wizards begin the game face-down on the play area, forming three columns with your opponent’s wizards.

Your boss also starts face-down on the play area, to the left of where you will be eventually placing your summons.

Wand: Wizard position (starts face-down)

Summoning circle with hand: Summon position (not on the play area when the game starts)

Evil horns: Boss position (starts face-down)

To paint a picture of how this looks, imagine it like this: The two innermost rows of cards, which include the summon and boss positions, is the battlefield. This is where the creatures players use fight against each other. Behind your summons is your castle wall, followed by your wizards, who are up in the castle with you. Your wizards are casting their magic down onto the battlefield from up high in your castle.


The game is played by taking turns, switching back and forth between the players. You’ll need to determine who will go first.

  • If you’re playing casually, then you can play something like rock-paper-scissors, with the winner deciding who goes first. (Just make sure to use a luckless method to pick who goes first. And yes, RPS is not luck. You can debate me on our Discord)
  • If you’re playing competitively, then follow the rules listed later in the guide.

Once you are ready, begin the game!

Turns are split up into 4 sections, called phases.

  1. Phase 1: Startup Phase. During this phase, you ready all of your face-down wizards and face-up cards. This means you take any of your face-down wizards, or any cards you have on their sides, and turn them face-up and facing forward. You also double your vim.

    Example: If it is the very first turn of the game, you will have 3 face-down wizards and 1 vim. After you ready your wizards and double your vim, you will have 3 face-up wizards and 2 vim. Then your startup phase ends, and you move on to the next phase.

  2. Phase 2: Summoning Phase. During this phase, take any number of your wizards and turn them face-down, then place summons from your castle directly in front of them. This is called conducting summons. Make sure you match the summoning condition of the summon you want to play, which is found above the card’s ability box. A face-down wizard loses its ability while it is face-down, but your wizards will turn face-up again during your next startup phase.

    Example: This example will use Forest Sage and Essence of Nature, the wizard and summon pictured earlier in the guide. During your summoning phase, you can turn Forest Sage face-down to play Essence of Nature from your castle, since Essence of Nature’s summoning condition is “Conduct a summon with Forest Sage.” You could also use Forest Sage to play any summon from your castle that has the condition “Conduct a summon with any yellow wizard“, since Forest Sage is a yellow wizard. (Note that Conducting a Summon does not cost vim)

  3. Phase 3: Main Phase. This phase is where most of the action happens. There are 4 things you can do during this phase: Attack, Cast Spells, Use Abilities, or Conduct a Summon on Your Boss. Attacking, Casting Spells, and Using Abilities can happen as many times as you want, if you can pay the costs to do so. You can also do any of these actions in any order or combination you want.
    • Cast a Spell: Pick the spell you want to play from your spellbook. Then, pay its vim cost, which is found on the top-right of the spell. Then reveal the spell to your opponent and use its ability. After the ability is done, place it in your graveyard.
      If the ability has italic text at the beginning, then it has a condition that must be met before it can be played. For more information, see the Abilities section later in the guide.

      If the ability has the word enchant, you place the spell underneath a valid card. When the enchanted card is removed from the battlefield, place the spell in your graveyard. You can even enchant your opponent’s cards! But when they are removed from the battlefield, the spell goes to your graveyard, not theirs.

    • Attack: First select one of your summons. Then pay the cost to attack, called Acting. By turning a card on its side, you spend its action. A card only has one action while facing forward, and when it turns on its side, it loses its action. In other words, a card on its side has already acted, and cannot act again until it returns to facing forward. This means that an acted summon cannot attack, since the cost to attack is to act.

      Then, select any other summon on the battlefield to attack. You can even select one of your own summons! Remember: A summon can attack any other summon on the battlefield, regardless of where the summons are located.

      Finally, compare the Strength values of the battlers, which is found on the bottom right of the summon. Strength is a number that represents both the “attack power” and “health points” of the summon. Both summons are Dealt damage equal to the other’s strength, and will Take damage up to the amount of strength they have. A summon cannot take more damage than its strength, since strength also represents its health points.

      For example, when a summon with 500 strength battles a summon with 2 strength, the weaker summon is dealt 500 damage, and the stronger summon is dealt 2 damage. Both summons take 2 damage, with the stronger summon being left with 498 strength, and the weaker summon being left with 0 strength.

      Finally, check if a summon’s strength became 0. If a summon’s strength becomes 0, it is defeated. Send it to the owner’s graveyard after using any abilities that happen when a summon gets defeated.

    • Player Attack: You may also attack a player to lower their life. To attack an opponent, the column of the summon you are attacking with must not have a summon in it. Act with the attacking summon, like normal, and then declare that you are player attacking.

      (You can ignore wizards when player attacking. Think of them as being up in the castle with you, looking down on the battle occurring below them)

      Your opponent, at this moment, may choose to defend the attack by taking a summon in an adjacent column and moving it over to block. If they choose to block, a normal battle happens. Otherwise, the opponent is dealt damage equal to the attacking summon’s strength. Note that there is no cost to block, and the attacking summon is not dealt damage for successfully attacking a player.

      An opponent who has not started their first turn is treated like they haven’t walked up to the battlefield yet. This means you do not have an opponent until they start their first turn, so you are unable to attack them and any ability that would effect them does not.

      But, you may attack yourself, if you feel like it.

    • As a review of attacking: A summon may attack any other summon, but in order to attack an opponent, the summon you’re attacking with must not have another summon in front of it.

    • Summon Your Boss: First, look at its summoning condition. If that condition is met, you may turn your boss face-up during your main phase. They are treated exactly like summons and can do everything a normal summon can do, including declare attacks, get attacked, use abilities, etc.

      However, because these summons have the special name “boss,” they have some additional rules attached. (These rules can be visualized if you picture your boss as if it is covering your entire battlefield)

      • Bosses are not treated as summons in the case of abilities. If an ability says, “Deal 3 damage to a summon”, it will not work on a boss. Likewise, if an ability says, “Deal 3 damage to a boss”, it will not work on a summon.
      • Bosses can block player attacks even if they aren’t in a column adjacent to the attack. However, when a boss blocks, it does not leave its current spot.
      • Bosses can only attack an opponent if they have no summons and have no face-up boss. In other words, if their battlefield is completely open.
  4. Phase 4: Ending Phase. During this phase, nothing special occurs. Some abilities may occur during this phase. Next turn!


To properly read an ability, break it down into 4 sections. As an example, we’ll use the ability of Forest Sage, pictured earlier in the guide: “During your main phase, [act]: A summon you control gains 2 strength.”

  1. The condition, which is always in italics. Abilities can only be used when the condition is met. If there is no condition, the ability is always active. The condition for Forest Sage is “During your main phase”.
  2. The cost, which is always in bold and surrounded in brackets. Abilities can be used as many times as you want, if you can pay the cost for them. If there is no cost, then there is no sacrifice that must be made to use it. The cost for Forest Sage is “[act]”, which means it must turn on its side to use its ability.
    Note that if there is no cost for an ability, you do not need to act to use that ability.
  3. The optional/mandatory symbol, which is either a circle with a dot in it or a circle with an arrow in it. This symbol will always appear at the beginning of a card’s ability.
    • Circle with a dot: Optional. You may use the ability if the condition is met, and the cost can be paid.
    • Circle with an arrow: Mandatory. You must use the ability if the condition is met, and the cost can be paid. All abilities that are mandatory will also have the word “must” in it for clarification.
    • Forest Sage’s ability is optional because has a circle with a dot in it, and it does not say the word “must” in the ability text.
  4. The ability itself, which is always normal text. This tells you what happens! In this case, the ability is “A summon you control gains 2 strength.”

To put it all together, “During your main phase, [act]: A summon you control gains 2 strength” is an optional ability that can be used during your main phase if you can turn Forest Sage on its side. If you do, you can pick a summon and buff it!

If multiple abilities would occur at the same time, the player whose turn it is decides in what order the abilities happen, but they must make all mandatory abilities go first. Then, check the next ability and see if its condition is still met. If it isn’t, do not apply the ability text.


Thank you for playing BOS! These are all of the rules you need to get started. If you have any questions, please reach out to us in our Discord server.

Competitive Rules

If you are planning to participate in BOS tournaments, or if you’re looking for a more serious match, there are some additional rules that you’ll need to follow.


Players in a competitive setting have the option to create another collection of 10 cards to include in their deck called Reserves. These cards act as a backup to your normal deck, and you can swap cards from your reserves in between games. Your reserves can consist of a maximum of 10 cards, and can only have summons and spells in it. You must also still follow the restriction of a total of 3 copies of a single card in your entire deck, including your reserves.

All players who are attending a competitive tournament will need to construct their main deck and reserves prior to entering the tournament. It is highly recommended you try out your deck before the tournament starts, so you aren’t locked into a deck with a mistake in it. Play some games with people at the tournament venue! Then, when the tournament starts, you’ll submit your deck list to a tournament organizer and play with that for the bracket run.

Going First

To determine who goes first, you play a bidding game with your opponent. Each player secretly chooses a non-negative number. Then, they reveal it at the same time. The player with the higher number chooses who goes first, and the player with the lower number gets Ether equal to the amount they bid. Ether is a backup vim source that stays with you the entire game, and can be spent as a replacement for vim. For example, if you want to play a spell that costs 4 vim and you have 2 ether, you can pay its cost with 4 vim, or 3 vim and 1 ether, or 2 vim and 2 ether. Ether does not double.

As an example of the bidding game, player one bids 4 and player two bids 7. Player two wins the bid and can decide who goes first, and player one gets 4 ether.

Best of 3 Match

To play a competitive match of BOS, follow this flowchart:

  1. Greet your opponent and reveal your boss to them.
  2. Play the Ether bidding game to determine who goes first.
  3. Set up your battlefield. Remember to keep your boss, wizards, castle, and spellbook face-down so your opponent doesn’t gain any information.
  4. Play a game of BOS! At the start of player 2’s turn, they may decide what columns they want their wizards in.
  5. Play another Ether bidding game to determine who goes first for the next game.
  6. Swap out cards from your castle or spellbook with cards from your
    reserves. You may swap as many as you want, including none.
  7. Repeat steps 4-6 until the match winner is decided!



This is a mechanic to ensure a winner is declared every game.

At the end of your startup phase, if it is your 11th turn or later, you begin to decay. You decay once for each turn you’ve started after your 10th. For example, if it your 13th turn, you decay three times. When you decay, you halve your life and vim, rounding down.

This rule hardly occurs, because a typical game of BOS finishes with each player playing 3-6 turns. Decay is only meant to end extremely rare games that would normally end in a tie.

Time Control

Some tournaments may want their matches to run quickly to make sure the tournament ends at the correct time. If that is the case, the tournament organizer may provide timers to make sure players finish their matches. When a player runs out of time on their timer, they lose. The recommended setting is 15 minutes, with a 30 second delay every turn. (This delay means that your timer doesn’t start ticking down until you spend an entire 30 seconds during your turn)

When an opponent is taking an action during your turn, you may pause the timer until that action is completed. Some examples of actions the opponent could take during your turn would include:

  • Viewing your graveyard
  • Reading one of your cards
  • Asking for a judge
  • Choosing whether or not to block a player attack
  • Choosing whether or not to use an ability