Hakkonen said:
What is it that makes T5 unplayable?
In the original T5 edition, the book was littered with partial explanations of ideas, littered with errors and it was, in any case, difficult to digest as everything operated through coded acronyms and mathematical formula. It also tended to provide multiple systems to run things, or define things, or whatever - almost like 'choose your own system' in affect. There was no index, critically important for a large reference book, and the general organisation of the book was not intuitive.
Now, I'm a scientist, so I
like mathematical formula and the like, but when you actually tried to do something with the rules - like generate a character or run a combat it proved genuinely difficult to do so with the rules as written. It wasn't honestly fun to be frustrated either.
Now, I also own the most recent T5.09 PDF edition, and while I cannot honestly call it anything other than a complex system (and certainly a lot more complex than Mongoose Traveller), it is playable. Some systems are very detailed, however, and others left quite abstract. It won't be to everybody's taste, although it could be for some - and especially for those wanting some form of 'advanced Traveller' or at least, those wanting to see Marc Miller's final vision of the game he first created.