[Delta Green] Traits and the Corruption of Traits

My Delta Green-campaign uses a bunch of different rules and mechanics. In this post I’ll cover traits, the corruption of traits, Fortune-points and Insight-points, and how these mechanics keep the investigators alive long enough to be alienated.

The rule in brief

  • Choose three traits – positive or negative
  • Each trait can be used once pr. session to flipflop a skill check.
  • The player can earn a Fortune-point, if the trait is used to hinder the skill check.


Flipflop is borrowed from Unknown Armies. With a flipflop, you shift the numbers on the percentile die, so 73 becomes 37, 81 becomes 18 and 55 is still 55.

The idea that a trait can be used in both a positive and a negative manner is borrowed from Mouse Guard. So the trait clumsy is no worse than the trait dextrous, since the player chooses when the trait is applied.

The rule in detail

Each character possesses three traits. A trait can either be positive or negative, it can be physical, social, mental etc. Since the Call of Cthulhu is not about playing crazy people battling horrendous beings, but about people having mindshattering revelations about the truth of the world, they live in, the players cannot choose insanities

When a roll is failed, the player can choose to activate a trait, and then briefly describe how the trait plays a roll in granting the character succes. The dice are then flipflopped.


The player can choose to gain -30 penalty to the skill check or to force upon himself a skill check (GM is final arbiter here) in order to earn a Fortune-point. This is chosen before the dice are rolled.

Fortune-points can be spend, when a critical failure is rolled. This changes the critical failure to a regular succes, and this is due to some outside factor randomly helping the character. Critical failure is when a pair is rolled, and the skill check is failed, e.g. rolling 88 on a Driving Car-70%. Again this is borrowed from Unknown Armies.

Corrupting the trait

This is second part of the rule, and this rule is invoked by the GM, when a character looses 5 or more points of sanity in one go, and the situation feels right. At present this is a very soft way of handling the rule, and it needs some development, but that will have to come in later.

When a trait is corrupted, it is replaced with a new trait, that reflects the mental stress the character have been through. This can be anything from mental stress to a guilty conscience, as long as it is a negative trait. The original trait can be regained in the same manner as characters can be cured of their insanities.

A corrupted trait can be used to flipflop failed rolls as a regular trait, and it can be used to earn points. The player earns Insight-points instead of Fortune-points.


An Insight-point can be spend instead of paying 5 sanity-points, when using spells or magical items. This allow the character to cast spell without loosing sanity.

The purpose of the rule

One aspect of the traits are simply to grant the players more successes, and to have them describe their characters’ traits in the process. Secondly it encourages the players to risk failing once in a while in order to earn points, that protects them from critical failures.

The second aspect is more important. The corrupted traits represents the alienation of the character from his surroundings, and in part from the player himself, as the character’s traits are replaced with new traits dictated by the GM, and at the same time making the original traits unavailable. Futthermore the Insight-points encourages the use of spells and magical items, which in themself brings the characters closer to the hidden world of the Cthulhu mythos.

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