d10's are 10-sided numbered polyhedral dice

VAST uses a basic d10 mechanic. Whenever a character is required to make a skill check they roll a number of d10's to determine the success outcome. The number of dice is referred to as a dice pool.

Successes are measured by how many die are rolled that are a 7 or above (i.e. 7,8,9,10). Note that many d10s have a 0 instead of a 10 - in this case the 0 counts as a 10. Based on those rolls the amount of Success is calculated, as per the table below. A critical success, which is a 10, counts as a bonus 1 towards the Success count. However a critical fail, which is a roll of 1, counts and a negative one towards the Success count.

Initiative, Space Combat and Bridge Merit rolls do not count criticals. There is no level of success for Bridge Merit rolls, only a success or failure, and they only require a success count of 1 or above to be considered a success.

Success Count

  • Less than 1 - Critical Failure
    • You fail to do the action you were trying, and there may be consequence for failing
  • 1-2 - Failure
    • You fail to do the action you were trying
  • 3-4 - Minor Success
    • You partially succeed on the action you were trying, and may potentially have to attempt further skill checks in order to fully complete the action
  • 5-7 - Medium Success
    • You succeed in the action, but with no bonuses or consequences
  • 8-10 - Full Success
    • You succeed in the action, and in doing so may be rewarded for doing it so well
  • 11+ - Outstanding Success
    • You succeed in the action and were awesome, with additional rewards beyond what would be the normal result of succeeding


Roll of 14 d10s: 1, 1, 2, 3, 5, 5, 5, 6, 6, 7, 8, 8, 9, 10.

  • Successes: 5 (7, 8, 8, 9, 10)
  • Critical Successes: 1 (10)
  • Critical Failures: 2 (1, 1)
  • Success Count = 5 + 1 - 2 = 4 = Minor Success

Adding Willpower to Skill Checks

Before a roll is made, a player can use their willpower to add dice to the roll. For each willpower sacrificed, one dice is added to the skill check.

Willpower can not be used on Bridge Merit rolls.

Contested Rolls

In combat or social situations, contested rolls can be used to determine the outcome of an encounter. In this case, the relevant skill check is made by each party, with the winner determined by who has the greater Success Count.

Contested rolls are most often used in combat to determine whether an attack hits or misses, and in social encounters to determine if a character can convince another character of their point of view. In social situations, a failure can still have a limited effect on the opponent.

Tied Rolls

In the event of a tie on a contested roll (i.e. both parties roll the same number of successes), the result of the encounter always goes to the defender.

Behind the Scenes

  • Early episodes of VAST did not count critical successes or critical failures towards success counts. It is unknown whether this was an oversight or if the concept was added to the game during production.

See also