Settembrini said:
Mmm. Or like any other version of Traveller?
No, not like every other version of traveller.
TNE had multiple actions per turn, with high initiative characters not only acting first, but acting more often. Of course, that could be ignored and just "Go round the table", which many GM's did...
MT had no initiative system, only an interrupt system.
In MT, the ref decides which side goes first, and that side gets one character/vehicle/unit action, which may be interrupted by another side. THe interrupting unit may likewise be interrupted. But any action taken to the point of the interrupt has occurred; and if still capable of action post interrupt, they get to finish their action. Then, if the other side still has characters/units/vehicles which have not yet acted, one of those goes (subject to interrupts by any units not activated yet), and so forth.
T20 has an initiative roll, work in initiative order.
CT left it up to the Ref, but generally was a SIDE at a time.
T4 was much the same.
All the above had 5 second combat rounds.
GT uses an initiative score, and has an option of move phase and act phase, or each takes full turn on their initiative. (Actually, the move each then act each was an option designed for G:Autoduel 1E, and ISTR it made it into Compendium 1 or 2...) But then GT, due to being GURPS, has more options rules-wise than any other.
TravellerForHero will use the Hero System initiative system: typically 2-4 actions per turn by character speed, 12 sec turns (12x 1sec phases), and each declares in dex order within the phases where they get to act.