C&D was based on Twilight second edition. TNE was as well, but incorporated the d20 upgrade. The d20 version was back-ported to Twilight as version 2.2. Earlier versions of the house system (Twilight 2nd, DC, C&D?) used d10s for task resolution and d6s for auto weapons fire. The later upgrade used d20s for both and changed the initiative rules. The quickest way to check is to look at the task rules. If there are any mentions of d20s, you have the later version of the house system.
Twilight 1st ed was a different system, IIRC, using d% for task rolls. I shudder at the thought of its vehicle combat rules being used for TNE. (They were pretty detailed.)
Twilight 1st ed was a different system, IIRC, using d% for task rolls. I shudder at the thought of its vehicle combat rules being used for TNE. (They were pretty detailed.)