<aside> 💡 I also asked how it could made cumulative.

</aside>

Your concept for a fear mechanic in a tabletop RPG using Traveller's 2d6 system is intriguing and adds an extra layer of challenge for players. Here's a refined version that incorporates your idea and ensures it's cumulative and dynamic:

Fear Mechanic for Traveller's 2d6 System

Introduction: Fear can be a powerful and debilitating force. It can cause physical reactions, cloud judgment, and lead to irrational decisions. In this mechanic, fear will be represented by a cumulative Fear Die that impacts your character's actions.

Mechanic Overview:

1. Fear Die (FD): Each character has a Fear Die that starts at 0 (no fear). The Fear Die can increase or decrease based on the character's experiences and actions.
2. Rolling the Fear Die:
   • After each significant event or failed roll that would reasonably induce fear (e.g., encountering a terrifying creature, witnessing a gruesome scene), the character rolls a Fear Check (2d6) against a set Difficulty Threshold (DT).
   • If the roll is below the DT, the Fear Die increases by one step (d2, d4, d6, d8, d10, d12).
   • If the roll meets or exceeds the DT, the Fear Die remains the same or decreases by one step if a high threshold (e.g., rolling 12) is met.
3. Using the Fear Die:
   • When a character attempts an action under stress or in the presence of fear-inducing stimuli, they must roll their Fear Die.
   • Subtract the result of the Fear Die from their primary roll (2d6 + relevant modifiers).
   • This subtraction represents the impact of fear on their performance.
4. Adjusting the Fear Die:
   • Characters can reduce their Fear Die through successful Fear Checks, calming actions, or supportive role-playing moments (e.g., encouragement from allies, taking a moment to compose themselves).
   • Special circumstances (heroic acts, overcoming fears) can reset the Fear Die or reduce it significantly.

Example:

• Initial Fear Check: Beronix (Wesley's character) encounters a terrifying alien creature. The DT is set at 8. Wesley rolls 2d6 and gets a 7. The Fear Die increases from 0 to d2.
• Action Under Fear: Beronix attempts to shoot the creature. Wesley rolls 2d6 and adds his shooting skill (+2). He gets a total of 10. Wesley then rolls his Fear Die (d2) and gets a 1. The final result of his action roll is 9 (10 - 1).
• Calming Down: After the encounter, Beronix finds a safe place to rest. Wesley role-plays calming down, and the GM allows a Fear Check with a DT of 10. Wesley rolls a 10, reducing the Fear Die from d2 back to 0.

Advantages:

• Dynamic: The Fear Die mechanic creates a dynamic and evolving challenge for players, reflecting the real impact of fear on performance.
• Role-Playing Opportunities: Encourages players to role-play their characters' fear responses and coping mechanisms.
• Cumulative Effect: The Fear Die can increase or decrease, representing a character's fluctuating fear levels.

This mechanic can be adjusted based on the setting and the desired level of difficulty. By making fear a tangible mechanic, you add depth to your game and provide players with an immersive experience.