Ghostbusters via Tricube Tales: Challenges

[The following article, describing how challenge resolution works in Tricube Tales, originally appeared as a response to a comment on this article. Note: I changed the word "task" to "challenge" in keeping with the terminology used in the rules. In a future article, I will likely tackle the subject of translating the antagonists from Ghostbusters to Tricube Tales.]

Challenges are resolved by rolling one to three six-sided dice. The GM will call for a trait roll (agile, brawny, or crafty) and state a difficulty (4, 5, or 6). If any die equals or exceeds the difficulty, the character succeeds.

If the challenge matches both the character's trait and concept, the player rolls three dice. If the challenge matches one, but not both, the player rolls two dice. If the challenge matches neither the trait nor the concept, the player rolls one die.

Characters start with 3 points of karma each. If the player wants to reduce the difficulty after rolling, the player can spend 1 point of karma to reduce the difficulty by 1 if it can be related to the character's perk. If the player wants to increase the difficulty before rolling, the player gains 1 point of karma and the difficulty increases by 1 if it can be related to the character's quirk.

Dr. Raymond Stantz
Trait: crafty
Concept: Ghostbuster
Perk: expert on Occult Studies
Quirk: overly enthusiastic

So, if the GM says deciphering the mystical writing in a pentagram requires a crafty roll with a difficulty of 5, Ray rolls three dice (because he's crafty and it fits his concept) and succeeds if any of them come up 5 or 6. After rolling, he can choose to spend a point of karma and reduce the difficulty by invoking his perk (Occult Studies expertise). If he wants to regain karma, he can raise the difficulty to 6 before rolling the dice by invoking his quirk (overly enthusiastic).

If the GM says firing the proton pack at the lethargic poltergeist requires an agile roll with a difficulty of 4, Ray rolls two dice (because he's not agile, but he is a Ghostbuster) and succeeds if any of them come up 4, 5, or 6. He can probably justify using his perk or his quirk to modify the difficulty.

If the GM says using a crowbar to bludgeon a hostile robot requires a brawny roll with a difficulty of 5, Ray rolls one die (because he's not brawny and the task does not fall under the purview of being a Ghostbuster) and succeeds if it comes up 5 or 6. He cannot invoke his perk since robot-fighting is unrelated to Occult Studies, but he could use his quirk of being overly enthusiastic to raise the difficulty and regain karma.

[Edit: I replaced "Explanations and Examples" with "Challenges" in the article's title.]