Operations as defined by the Annulus ruleset includes anything that adventurers do to manipulate, analyze, investigate or reform mechanisms, objects, structures or scenes to achieve a desired result. This includes but isn't necessarily limited to activities such as:

• Picking a lock.
• Hacking into a database.
• Disabling a mechanical trap.
• Patching up a wounded companion.
• Picking up the trail of a fugitive.
• Forging official documents.
• Sabotaging a wagon wheel.
• Jamming a door shut.
• Hotwiring a motorcycle.
• Fixing an engine.
• Checking a crime scene for clues.
• Drawing a magic circle.
• Building a raft from driftwood and junk.
• Unclogging a toilet.
• Performing surgery.
• Escaping from confinement.
• Removing a key from around the neck of a sleeping ogre.
• Making a decent copy of the writings in a ruin.
• Reforging a sword of legend.

All operation activities use the same method to resolve success or failure and are known as Operation Challenges.

The difficulty of a given operation challenge is measured in dice, with two-die operation jobs being the simplest. As more and more dice are added to a job, it comes to represent a greater and greater level of challenge.

To set up an operation challenge, the GM rolls a number of 12-sided dice equal to the challenge level of the job in question and places them in a line in the order they were rolled. For example, if the GM rolled a 3, 5 and a 3 for a three-die challenge, they would line them up like this:

[7][9][7]

The goal of a tinkering 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 an automatic success no matter what number is displayed on said die.

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 creature that is in the vicinity of the operation can use 1 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 1 action, leading to a success and completing whatever goal the operation was meant to accomplish. Adjustments are not guaranteed to succeed, however- sometimes they result in a jam instead of the desired number change (see below).

Every time a creature makes an adjustment on any die in an operation chain, they must first roll a check to see if they screwed something up or otherwise made things more difficult for themselves. This is a standard four-die check. If the check has a number of successes equal to or greater than at least half the dice in the current challenge- for example, a six-die challenge requires three successes. If the check fails, the die jams and its number is not changed.

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 (this doesn't work if your dice read the same in either orientation), 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.

Sometimes not all the parts of an operation are immediately apparent. When the GM rolls the requisite number of dice for a challenge, they first secretly roll an equal number of six-sided dice in a line in the order that they are rolled where none of the players can see. These six-sided dice correspond to the player-visible twelve-sided dice. Any of the six-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 six-sided dice that display a 1.

For example, say a GM decides that a given challenge has a difficulty of four dice. They secretly roll four six-sided dice and get the following results:

[5][1][4][3]

The presence of a 1 means that one of the dice in the challenge is hidden, so the GM rolls 3 12-sided dice in plain view of the players. The players solve the current challenge in all ways as if it were a 3-die challenge, except that 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”. Hidden dice are revealed in order from left to right (the GM might have to point out which end of the chain they are revealing hidden dice from).

As a review, this is the basic sequence of events for a tinker challenge:

1. GM secretly rolls as many six-sided dice as the challenge calls for and lines them up.
2. GM then rolls a number of 12-sided dice corresponding to the number of six-sided dice that are not displaying 1s and lines them up for the players. The GM announces the true number of dice in the challenge if there are hidden dice during this setup phase.
3. Player points to a die and declares what they wish to do to it (such as “change this 4 to a 5.”) This costs the player 1 action.
4. Player rolls for jamming. If the result is not a jam, their declared plan of action is carried out.
5. If the result is a jam, the die they were pointing to immediately jams on its current number and is not changed in any way than before they made their declaration.
6. Player continues until either finishing the challenge or enough dice are jammed in such a way as to make that impossible.
7. If the challenge is finished with no hidden dice, the players achieve their objective. If not, a single hidden die is revealed and inserted into the chain in the appropriate location.

Knacks are special tricks or mechanical advantages your adventurer can use to make overcoming operation challenges easier. See the Knacks page for more details. More difficult challenges will almost necessitate the use of knacks.

Multiple creatures can work together to pass a single operations challenge, each taking a turn to make adjustments or use advantageous op abilities they may possess. However, only up to four creatures may collaborate on a single challenge at once. Once four distinct creatures have all interacted with a single challenge in pursuit of the same goal, no more may participate.