I'm super excited to tell the fun stories and strange developments that have happened as Rift was being developed, but a little history lesson seems important first.
Right this second, Rift is version .42. I use a complex system to determine when I change the version number, mostly concerned with a vague feeling of whether I've changed a lot of things or a few things, and ultimately decided by whether I can be bothered to change the number in the bottom corner of the cards.
There is a bit of reason to it, though. To me, .42 means "second minor adjustment to the fourth major iteration". I don't spend a lot of time worrying about what a minor adjustment is or isn't - it's mostly defined by time: time drafting changes into the actual card text in Indesign, and time spent printing, cutting, and sleeving new prototype cards.
The major versions, though, have a solid progression to them. This is how I'd sum up the major versions:
.1x: Crap. Let's not talk about it (until later).
.2x: An idea-prototype with hand-written cards that could be played on any game board (whooooooaaaa). The theory was to have a compact combat game with a fun gimmick; if you were bored and at a convention or game store, you could whip this game out and play through a quick duel on the island of Catan, or in the world of Arabian Nights, or across the war-torn planet of Risk 2210. I'm excited to talk more about what worked and didn't work about this idea.
.3x: But (spoilers!) the "any game board" idea was doomed, and version .3 was the first one to have its own game board. That change echoed through the rest of the game, too, and changed the design of the cards, the characters, and the rules themselves. This is the first version that was actually interesting to play, and this paradigm lasted for a long time. I would change a set of cards and go to version .32; change a couple rules and go to .33, and so on, all the way up to .39.
.4x: The fourth and current version brought a couple big changes, but I also ran out of .3x numbers. On a more emotional level, though, moving to .4 felt like a good way of recognizing that I was getting close, and that the game probably wouldn't need to go through any more gigantic changes. I have no idea if I'm right about that, but there's not much to go on if you're not going on instinct.
There's a tension in the versions, for me, between thorough testing and incremental improvement. Sometimes, I'm sure that a card or mechanic is wrong - either it doesn't fit, or it's too powerful, or it just doesn't feel right. Often, though, that's based off of a sample size of just two or three games with the current version. Do you make the change or test more? The closest thing I've found to the right answer is to deal with an icky feeling for at least one more play-through, and if it's still icky, then change it. Sometimes, that means changing entire mechanics or cycles of cards - but what's the alternative? Making something that makes you feel icky? Seems like a bad choice.
Anyway, I think version .4 will be sticking around for a while, but I'm also 100% sure that .42 won't be the last, either - mostly, because I already have a list of small changes for v.43 that I haven't put into the indesign file yet. I'll keep making adjustments until I finally have to lock everything down - and then, Rift will hit version 1.0. I can't wait!