Ironbound uses a simple, unified system to resolve most uncertain actions. When a character attempts something whose outcome is uncertain, the player rolls the appropriate dice, adds the relevant modifiers, and compares the result against a difficulty set by the Game Master. The result is not merely a success or failure; Ironbound uses five degrees of success, allowing exceptionally good or poor rolls to produce correspondingly greater consequences. These rules form the foundation upon which combat, exploration, social interaction, magic, and every other aspect of the game are built.

The most common die roll that a player or the Director will make is an attribute check. To perform an attribute check, the player rolls two ten-sided dice, adds them together, and adds the modifier from the requested attribute. Compare the resulting total to the following table:

Any die roll can be modified by favour or slight. Favour represents a temporary or fleeting advantage, whereas slight represents a temporary setback or difficulty to be overcome.

When a character makes a roll with favour, they add one additional die to the pool being rolled. If the die roll includes multiple types of dice, the player chooses which type of die to add. After rolling, the player may discard any one die from among those rolled. If the roll has multiple instances of favour, the player adds as many additional dice to the roll as they have instances of favour, and discards a number of dice of their choice equal to their instances of favour.

When a character makes a roll with slight, they add additional dice to the pool being rolled, in the same manner as rolls made with favour. However, after rolling, the player must discard a number of dice equal to their instances of slight. They must discard the dice showing the highest values first. If the roll included multiple types of dice, compare the absolute value showing on the die, rather than their values relative to the maximum possible result on each die. For example, a 5 rolled on a d12 is discarded before a 4 on a d4.

Instances of favour and slight cancel each other out, until only favour or only slight remains. Multiple instances of either favour or slight stack. A character with three instances of favour rolls three additional dice, then discards three dice of their choice; a character with three instances of slight does the same, but must discard the three highest dice.

When favour is declared as forward, the player can choose to add it to any roll, or save it for use later. They must choose to add any instances of forward favour before rolling the dice.

A roll can benefit from no more than one instance of forward favour. If a character has multiple instances of forward favour, they cannot combine them on a single roll; each instance must be applied to a separate roll. However, forward favour can stack with normal instances of favour and can be used to cancel an instance of slight.

Choosing an activity that grants one or more Holds will also specify when those Holds can be spent and the options available when spending them. Holds can only be spent when it is not your turn. When a circumstance allows you to spend a Hold, you may spend only one Hold per trigger.

A character can have Holds from only a single source at a time. If a character has Holds from one activity and performs a different activity that grants Holds, they lose any Holds granted by the first activity.

Every character gets access to the Ready a Response activity and the Stand In Defence activity. Some classes offer other activities that grant Holds.