CUF tweak...not complete
I've been futzing with my own ideas.
I have not read the combat rules for MegaTraveller in a long while. I knew 2300AD before I ever heard of MegaTraveller and the older Classic Traveller. That being said, the rules for CUF and initiative I've come up with here might not work with CT/MT...I have to do more reading.
Coolness Under Fire
(Note: Combat rounds are thirty seconds long, as in 2300AD. Unlike the official 2300AD rules, however, you are not limited to just two actions in a round. In this system you can have up to five actions, depending on your initiative roll. Skills are also limited to a rating of 5. For now the skill improvement system I’m using is from MT, i.e. ATs.)
The trait Coolness Under Fire (CUF) is rated like a skill, i.e. from 0 to 5. It starts at 0 for everyone, and for every career term where lethal violence presents a risk, it increases by one, and can be improved with ATs, just as skills are, with this exception: you are not limited to two ATs/year for CUF.
Your CUF limits your attack skill, and it replaces your DEX for combat initiative purposes. If your CUF is lower than your attack skill, use the lower of the two values. CUF never limits your defense. CUF applies to firefights as well as fistfights; it’s a general indicator of how you perform under combat stress.
Your initiative governs how many actions you can take in a combat round. To determine your initiative, roll 2d6 + Relevant Skill + CUF (note that your skill rating is limited to CUF for initiative purposes, too).You get your first action on the initiative count that matches your initiative roll, and then one more action for each half-count thereafter (round down). Example: With an initiative of 4 you act first on initiative count 4, then 2, then 1. With an initiative of 7 you act first on initiative count 7, then 3, then 1. An initiative of 8 or higher sees you acting four times in a combat round.
If you are surprised, your initiative roll is halved. Someone with a high enough initiative roll that gets surprised could still act before an ambusher/attacker with a lower initiative, however (a model for combat reflexes). In cases of surprise and/or ambush, initiative ties go to the attacker.