2d6 (or 2 6-sided dice) are all you need, easy enough to suffice the goal of BITS to be simple without being too simple.
6-sided dice are the most common dice a player’s likely to have in a sock drawer or at least any other game, so sticking with that fixes the issue many games have of having a museum of different many-sided dice.
As for having buckets of dice at any time, 2 is a great number. 2 breaks the linear drudgery of a single die, giving a lovely curving range which has double digits and makes even a minor change in a roll’s value possibly momentous. (The next section explains the latter part.)
No, BITS is not for the folks who bring a satchel of colorful dice to every gaming table. Yes, BITS is for the player who likes time spent on gaming vs. digging for dice. 🎲🎲
Use the Dice When…
There’s a chance that a game-character’s or -creature’s actions could hurt itself, hurt something else, draw unwanted attention, change how others act, cause the future actions not to be taken, or otherwise impact how the game will progress (or not) from the point of action forward.
You have to test for these, tests being times you roll the dice. The value of the dice (and any other values added to it) must meet or exceed a threat value for a given course of action. Threat may be the meanness of a monster, the narrowness of a cliff edge, or the reluctance of a princess to grant your wish.
When 1 or more tests are required to resolve conflict, those are trials, which come in 3 flavors: Combative (physical violence between creatures), Environmental (surviving dangerous conditions), and Social (convincing others to act). Each uses the BITS values for whatever action a player would like to take, which has made play faster and players more confident in their decisions.
The order of a trial (who rolls dice first, second, etc.) comes from an initiative order roll at the start of a trial. The highest value (with their highest BITS value added) goes first. If the value is odd, the order is clockwise (to the left), counterclockwise if even, each player (and the GM) taking tests for all the things they control at once. (Thus, BITS removes the need to keep track of a bouncing arrangement of who rolls dice when!)
Designer note: Categorizing and defining when to roll is an aim to remove ambiguity from the dice. In popular games, the numbers from a roll only matter concretely when a player is in combat, using subjective measures or a boat-load of skills or talents to resolve anything else (e.g. D&D). With BITS, dice roll for anything, removing subjectivity and increasing both the utility of the BITS values and player attention (people like to roll dice 🤷♂️).
A quick note that BITS relies on addition and only addition virtually always. This isn’t the case some times. However, when this principle breaks, it is for small-number subtraction (i.e. 4), which the next section covers.
‘Vantage and Criticals
Advantage and disadvantage are not unique principles in games. Your actions have some boon or bane to them that does something to the conflict resolution, either rerolling dice, adding values to the roll, subverting other effects, or similar.
BITS, since the system has only 2 dice and we don’t want players “remembering” a roll either mentally or needing extra paper to jot a roll value down, relies on simply increasing or decreasing a roll by 4 for advantage or disadvantage, respectively.
(Here’s that point of the need for subtraction, a rare accommodation for the game experience over the addition-only principle.)
Critical successes or failures (criticals) require a wee bit more attention. A critical happens when the dice show double digits, the same value on both dice. What happens next depends on whether the value is above or below the threat the value needed to be.
Over the value (never on, as difficulty is only ever odd), the roll automatically succeeds. Under automatically fails. No other values necessary. (As BITS does not involve rerolling dice, there’s no concern as to getting doubles on a reroll.)
That’s the core mechanic of BITS! Roll 2d6 to see if your fiction happened the way you wanted it to, adding (and very rarely subtracting) values along the way.
Going to write up more on BITS in the coming weeks, going slowly to as BITS is actively undergoing edits and revisions 🙃 Stay safe! Have fun! Cheers ~