Think puzzles. But when you complete the first step, second step, third step, and/or so on, you put/set game.Quest1 = 1, game.Quest2 = 1, game.Quest3 = 1, and so on.

0 = Not started yet. 1 = Started. 2 = Completed. And more as needed.

if (game.Quest1 = 0) {
msg ("Quest ready." )
}

if (game.Quest1 = 1) {
msg ("Quest in progress.")
}

if (game.Quest1 = 2) {
msg ("Quest completed.")
}

I just came up with this at the top of my head. I use numbers to record or sort complicated values.

Also, I don't see why you need to make it a command, unless you do something like "Print game.Quest2." I recommend making an object and then putting it in the look description or read or some other verb. Commands just mess me up, I have broken entire games before with them, at least 3 times, and I fixed 2 of them, and 1 can be edited but it's in an unplayable state. If you are comfortable with commands though, go for it, don't let me stop you.

(I should put this in the library section if I can think of more to add to this....)

Pixie came up with a library for this very thing.

https://github.com/ThePix/quest/wiki/Library:-Quests