What has changed so much to make the third better for solo play?
I am reprinting a snippet of an old "Why buy Zeds 3, if I own Zeds 2" thread below (referencing the parts relevant to the solo-only player). It is bereft of component discussion, due to the fact I don't care deeply about components, and although Zeds 3 components are generally given high marks, some prefer the Zeds 2 components.
Also, (absent from my original post) Research is handled in a much comprehensive and interesting way (thumbs up from me), and much more elaborate and thematic "results" are described ("meh" from me).
Finally, the post below refers to my final playtest copy -- slight changes were then enacted that led to an "easier" game. Not a big deal as it is still a tough game, and using a few optional rules will return Zeds 3 to the terrifying "perfection' I remember.
"A major element of Zeds 3 is the cleaned up rules. I was never bothered by the original rules (started my game career age 11 playing much more complicated wargames), but Zeds 2 was quite a handful for most modern gamers. Zeds 3 makes a valiant effort to streamline the game and cut down enormously on the exceptional cases, but it sure isn't a basic game either. Well actually it is, through programmed instruction, a fantastic number of difficulty levels (both in complexity and victory chances) are available. I am a "dive in to the deep end of the pool right away" guy myself, but I can see the advantages of the new format. Which is completely irrelevant for the player that has Zeds 2 down pat.
Even for the "solo-only" player, there is subtle, but deep changes to the gameplay. The addition of "Chaos death", greatly complicates the equation. Zeds 2 is really a broken game if you play just to win -- the advantages of "turtling" around Town were vast, and the sheer number of nuances available left the ruthless player many "combinations" to exploit. If you play only thematically (and turn a blind eye to these gamebreaks), a fun time could be still be had -- but I play to win, to me the game is a two-player game in disguise (my opponent is the "absent" game designer), and playing a game I have a 95+% chance to win just isn't satisfactory. Zeds 2 had numerous "sleazy" wins to turn the Zeds into "petting zoo lambs", all gone in Zeds 3. I spent most of my free time for a month scouring Zeds 3 of imbalances -- I am fairly confident of a reasonably balanced game, both internally and externally (not completely confident, Zeds 3 has innumerable combinations of Hero mix and format, layered on some heavy random elements). That addition of "defeat by excessive Chaos' forces the "win-only" types to really play the game as intended (joining the thematic players in the terrifying difficulty). Can you win at the highest difficulty level? YES, but not always, and you will have to really earn it.
One last twist for the Solo-only player in Zeds 3, is capability to play "Co-op style", but solo. The Co-op game is much more frenetic than the solo-only -- many more actions per turn (and options), the Zeds are much more numerous and come on much faster. The original Zeds 2 seems very sleepy by comparison. For that alone, it may be worthwhile to take Zeds 3 "out for a spin", even if everything else leaves you unmoved.
There are also more Hero types, and a whole new class of player Unit (the Heroic Civilians), to combat some new evil cooked up. Some of the new material only affects the "Versus" game it is true, but a healthy amount can be enjoyed by everyone.
Still don't want to purchase Zeds 3? I understand, $60 is a chunk of money for game "that you already have bought" -- I am not paying it, I a have a beautiful little playtest kit, and I don't mind having an "unfinished" rulebook all scribbled over (also the fact I don't have to refer to it anymore helps). But I will never play Zeds 2 again -- Zeds 3 just has it beat, even as I am a "solo-only" player nowadays."