Animal Game Source circa 1973

From "GAMES, PUZZLES, and RECREATION-1" , a package containing 55 of the most popular RSTS-11 and RSTS/E recreational programs.
100 &"PLAY 'GUESS THE ANIMAL' WITH RSTS
150 &"THINK OF AN ANIMAL AND THE COMPUTER WILL TRY TO GUESS IT...":&
500 DIM A$(200)
525 F$="ANIMAL.GME"
	:ON ERROR GOTO 700
550 OPEN F$ FOR INPUT AS FILE 1%
	:INPUT #1%,N%
	:INPUT #1,A$(I%) FOR I%=1%TO N%
	:CLOSE 1%
	:A$(0%)=NUM$(N%)
	:ON ERROR GOTO 0
	:GOTO 1300
700 ON ERROR GOTO 1050
	:F$="$"+F$
	:RESUME 550
1050 READ A$(I%) FOR I%=0% TO 3%
1100 DATA "4","\QDOES IT SWIM\Y2\N3\","\AFISH","\ABIRD"
1300 INPUT "ARE YOU THINKING OF AN ANIMAL";Z9$
	:GOTO 1350 IF LEFT(Z9$,1%)="Y"
	:GOTO 4000 IF  LEFT(Z9$,1%)="N"
1310 IF Z9$="SAVE" THEN
		OPEN "ANIMAL.GME" FOR OUTPUT AS FILE 1%
		:PRINT #1%,A$(I%) FOR I%=0% TO VAL(A$(0%))
		:PRINT #1,CHR$(26%)
		:CLOSE 1%
		:GOTO 1300
1320 IF Z9$="LIST" THEN
	PRINT "ANIMALS I ALREADY KNOW ARE:"
	:PRINT RIGHT(A$(I%),3%), IF INSTR(1%,A$(I%),"\A") FOR I%=1% TO 200%
	:PRINT
	:GOTO 1300
1330 &"PLEASE RESPOND 'YES', 'NO', 'SAVE', OR 'LIST'":GOTO1300
1350 K%=1%
1400 K%=FNA%(A$(K%))
	:GOTO 3000 IF LEN(A$(K%))=0%
	:GOTO 1400 IF LEFT(A$(K%),2%)="\Q"
	:PRINT "IS IT A "RIGHT(A$(K%),3%);
	:INPUT Z7$
	:Z7$=LEFT(Z7$,1%)
1450 IF Z7$="Y" THEN 
	 PRINT "WHY NOT TRY ANOTHER ANIMAL"
	:GOTO 1300
2000 INPUT "THE ANIMAL YOU WERE THINKING OF WAS A ";Z9$
2050 PRINT "PLEASE TYPE IN A QUESTION THAT WOULD DISTINGUISH A "
	Z9$ " FROM A "RIGHT(A$(K%),3%)
	:INPUT Z8$
2100 PRINT "FOR A "Z9$" THE ANSWER WOULD BE";
	:INPUT Z7$
	:Z7$=LEFT(Z7$,1%)
	:IF Z7$="Y" THEN Z6$="N"
		ELSE IF Z7$="N" THEN Z6$="Y"
		ELSE PRINT "PLEASE ANSWER 'YES' OR 'NO'"
		:GOTO 2100
2200 Z1%=VAL(A$(0%))
	:A$(0%)=NUM$(Z1%+2%)
	:A$(Z1%)=A$(K%)
	:A$(Z1%+1%)='\A'+Z9$
	:A$(K%)="\Q"+Z8$+"\"+Z7$+NUM$(Z1%+1%)+"\"+Z6$+NUM$(Z1%)+"\"
2300 GOTO 1300
3000 DEF FNA%(Q$)
	:PRINT MID(Q$,3%,INSTR(3%,Q$,"\")-3%);
	:INPUT Z9$
	:Z9$=LEFT(Z9$,1%)
	:Z9$="N" IF Z9$<>"Y"
	:Z1%=INSTR(3%,Q$,"\"+Z9$)+2%
	:Z2%=INSTR(Z1%,Q$,"\")
	:FNA%=VAL(MID(Q$,Z1%,Z2%-Z1%))
	:FNEND
4000 &:&"O.K.  SEE YOU LATER.  HOPE YOU HAD FUN PLAYING!!":&:&
9999 END
ANIMAL.BAS