Count Dookkake said:
Really, this is one of the best answers.
When you finish a QFG game, it gives you the option of making a completion save.
You can then use that completion save to start a new game in any QFG game after it in the series with the name, class, and (approximate, and scaled up if you're skipping games) stats of the file you had. You can only load completion saves that are specially created after you beat a game, not just any old savefile. This is what makes the series different from a Baldurs' Gate, in that series you can just load any savefile from the first game and use that character in the second, just levelled up to the minimum level for the sequel if you hadn't reached that point yet. QFG actually makes you beat the games before you can move to the next... kind of annoying at times, sure, but an interesting system as well. Of course QFG games aren't anywhere near as long as BG games, so it's not like it's as time-consuming either...
The fact that you can use a completion save for any game after it in the series is a cool feature as well -- you can use your QFG1 completion save in QFGV and play a scaled-up version of that character. Also, there is one class, the Paladin, that is only available by completing certain quests in a few of the games. You can't just select that class from the start in any game in the series, you need to convert to it by doing the required quests and beating the game in question, and then can play it in any game afterwards by using that completion file.
... As for other things, the Baldur's Gate series if of course obvious, and I did the GBC Zelda Oracles password-game thing as well, and that giant Golden Sun conversion password too... for the Oracles games I think it kind of doesn't count, because the two games are often considered as two halves of one title because of how there's one final boss at the end that you only access by playing both. That's how I usually think of it, really. But still, it does definitely need mention, it was pretty cool to be able to continue your game from one cart on another.
