Me said:
Regardless of any official word, Mongoose Traveller and Traveller5 are related. But then I've never been a purist.
In what way, Rob?
The first stop Matthew made when he was carving out the core rules was Marc, who gave him CT and early chapters from T5. As we all know, Matt liked the CT/MT task system -- and I think that goes a long way to define a game. But the amount of structure borrowed from T5 is significant. Some of the subsystems for T5 weren't drafted at the time, so Matt used CT, which turns out to be just fine and quite usable.
T5 in MGT
The
careers come directly from T5. It is slightly different (adding the interesting "Drifter" career, and dropping a couple others), and the method is MGT's take, but the list is otherwise the same.
The
skills come directly from T5. It is slightly shorter in MGT (48 vs 64), and folds in some concepts (e.g. persuasion) which in T5 were moved under the task system in general, but the two lists are still closer to each other than anything else.
Mongoose's
starship design system stems from that draft of T5, blending in a bit of other rulesets (e.g. for armour) and some of their own neat stuff (drones). Some parts are verbatim from Early T5 -- the hull, bridge, drives, fuel, drive performance table. Some parts are simply influenced -- the sensor packages and computers are not the same, but show Early T5's influence. Check out page 107 -- see the power plant fuel requirements table? Does it look like an afterthought to you? It was missed -- I had to have it tacked on. And the table was generated from .... that early draft of T5.
Despite that, chargen and ship design "feels" quite different between the two systems. I am just pointing out the origin of many of MGT's rules are T5.
MGT in T5
On the other hand, MGT has also influenced T5. The example that comes to my mind is page 110, the "Luxuries" section. That didn't exist in Early T5, but has been adapted into the final document. Another example is on the next page, with "Fixed" weapon mounts. In Early T5 that didn't exist, but showed up in a modified way as "Firmpoints".
T5 and MGT
Finally, MGT was vetted by people who also vetted T5. This subtly allowed both rule systems to inform each other. For example, some MGT personal armor
values were vetted by me, as Marc was also developing the armor build rules for T5. At one point I had to establish a correlation function between MGT and T5's armor ratings, to gauge whether or not the armor ratings were reasonable (especially when they climbed into the stratosphere). I would then submit suggestions for value tweaks (seldom).
As it turns out, that opens up the possibility of using T5 to generate equipment for Mongoose Traveller, and porting innovative equipment from MGT to T5.