Operations as defined by the Annulus ruleset includes anything that is a complex, multi-step process that can benefit from teamwork. All operation activities use the same method to resolve success or failure and are known as Operation Challenges.

There are two levels of difficulty for operations: Normal and Advanced. Normal operations are the most common by far. Sometimes a GM might want to offer a more desirable outcome at higher risk by offering the players an Advanced operation instead of the Normal one they would otherwise have to solve. Interacting with a Normal operation requires a check of 4+ and interacting with an Advanced one requires a check of 7+.

To set up an operation challenge, the GM rolls a number of 12-sided dice equal to the total number of players capable of helping plus two and places them in a line in the order they were rolled. For example, if there are four players then the the GM rolls six dice. If they rolled a 7, 9, 7, 3, 11, and 5 they would line them up like this (assuming no dice start hidden, see Hidden Dice below for an explanation):

[7][9][7][3][11][5]

The goal of an operation challenge is to make it so every die in the challenge is exactly one number different from every die it neighbors. For example, a sequence of [1][2][3] is a valid solution, as is [3][2][1] and [1][2][1]. If for some reason an operation challenge has only one die, then it is automatically considered solved no matter what number is displayed on said die.

Sometimes not all the parts of an operation are immediately apparent. When the GM rolls the 12-sided dice for a challenge, they first secretly roll an equal number of four-sided dice in a line in the order that they are rolled where none of the players can see. These four-sided dice correspond to the player-visible twelve-sided dice. Any of the four-sided dice that display a result of 1, however, are considered “hidden”. The GM does not roll a corresponding 12-sided die for any of their four-sided dice that display a 1.

For example, say the GM secretly rolls their four-sided dice and get the following results:

[3][3][4][3][1][2]

The presence of a 1 means that one of the dice in the challenge is hidden, so the GM rolls five 12-sided dice in plain view of the players. The players solve the current challenge as-is, but then upon “solving” the puzzle, the hidden die is revealed and inserted into the die chain in the appropriate location. If there are multiple hidden dice, only one is revealed at a time and only when all visible dice are “solved”. The GM can reveal multiple hidden dice in any order they please.

In the above example of [7][9][7], the three numbers are not a valid sequence since the [9] is 2 points different from both of the [7]s beside it. Fortunately, any adventurer can use an action to attempt to change one of the dice to a number 1 higher or lower.

A creature could therefore change the above example into this:

[7][8][7]

with just one action, making that part of the sequence already “solved” and allowing them to turn their attention to the rest of it. Adjusting a die requires a check. Roll a trigrer die (12-sided) to see if you succeed- the number you need on the trigger die depends on the difficulty of the check and any training abilities you have. If an adjustment succeeds, the die's number is changed as desired. If not, the die jams.

When a die “jams” it becomes stuck on whatever number it currently displays. It is suggested that the die be marked in some way to visually represent its jammed status- one simple way is to simply turn it so that the number it displays is upside-down in comparison to the other dice, or physically move it slightly out of the line that the others are in.

A jammed die cannot be manipulated any further in any way. If dice are jammed in such a way that solving the operation challenge is impossible (such as by having two adjacent dice with numbers more than 1 point apart both jam) then the operation challenge fails.

Adventurers all have access to three Knacks (special abilities that manipulate challenge dice in specific ways) that can be used to make overcoming operation challenges easier. See the Character Creation page for more details. More difficult challenges will almost necessitate the use of knacks.

Knacks require a check to use. If a knack is attempted but the check fails, then that knack becomes unavailable for use for the remainder of the challenge but the challenge is otherwise unaffected by the check's failure. Succeeding with a knack gives you the effect of that knack and allows you to continue using it again in the same challenge.