Where?
I think you are assuming that you would have to have a load of If..Then statements - which isn't true!
Instead of
If Guess$="A"
If Guess$="B"
If Guess$="C"
and so on, you would use strings like this:
CLS 0
Alphabet$="ABCDEFGHIJKLMNOPQRSTUVWXYZ"
Do
Input "Enter A Letter: ";Guess$
Guess$ = Upper$(Guess$)
NotUsed = 0
For N=1 To Len(Alphabet$)
If Mid$(Alphabet$,N) = Guess$
Alphabet$ = Left$(Alphabet$,N-1)+Right$(Alphabet$,Len(Alphabet$)-N)
Print "Alphabet$: ";Alphabet$
Print
NotUsed = 1
Exit
Endif
Next N
If NotUsed = 0
Print "Already Tried That Letter!"
Print
Endif
Loop
When you run it, enter a letter and it is removed from the alphabet string. The next time you enter the same letter, it isn't in the alphabet string so you get the message that you've already entered that letter.
This is a simple but common method for this sort of thing and can also be used to deal cards from a pack in card games. Simply fill the string with all the cards and deal them randomly - removing them from the string as they are dealt so they can't be dealt again.
You might think that strings aren't a lot of use for 3D games, but you'd be surprised.
It's well worth taking the time to play with strings until my example code makes sense to you.
Any questions - just ask!
TDK_Man