Hunt the Wumpus is an early text-based adventure game, originally written in BASIC by Gregory Yob, and released in 1973. The player moves through 20 connected caves to hunt the gruesome Wumpus. The dungeon resembles the vertices and edges of a dodecahedron (d12 dice). The hero carries a bow and five magic arrows which can travel through multiple caves on a given trail. Beside the Wumpus, two bottomless pits and two Super Bats have to be avoided.
The program is split into eight functions and subroutines:
RESULT = IADJAC(IFROM)INTEGER) adjacent to room
IFROM (INTEGER).RESULT = INPUT()INTEGER), either
1, 2, or 3.RESULT = IRANDR()INTEGER).RESULT = EMPTY(IROOM).TRUE. if given room (INTEGER) is
empty, else .FALSE..CALL HELP()CALL INIT()CALL MOVE()CALL TURN(NEXT)NEXT
(LOGICAL) is set to .FALSE. if the game is
over, else to .TRUE..Additionally, three procedures that are not part of the ANSI/ISO FORTRAN 77 language standard are required:
RESULT = TIME()INTEGER). Required for the
initialisation of the pseudo-random number generator.RESULT = RAND(I)REAL).CALL SRAND(ISEED)INTEGER).Most modern compilers provide these through extensions.
The program in structured FORTRAN 77 has about 400 lines, including comments. Save the code as wumpus.f.
C ****************************************************************
C
C WUMPUS
C
C THE TEXT-BASED ADVENTURE GAME "HUNT THE WUMPUS" FROM 1973: FIND
C AND KILL THE HORRENDOUS BEAST WUMPUS THAT LURKS IN A CAVE FULL
C OF DANGERS. ORIGINALLY WRITTEN BY GREGORY YOB IN BASIC. PORTED
C TO FORTRAN IN 2023 BY THE ILLUSTRIOUS PHILIPP ENGEL.
C
C ****************************************************************
PROGRAM WUMPUS
EXTERNAL HELP, INIT, TURN
CHARACTER A
INTEGER ISEED, ISTAT
LOGICAL NEXT
C
C SEED THE RANDOM NUMBER GENERATOR.
C
ISEED = ABS(TIME())
CALL SRAND(ISEED)
C
C ASK FOR INSTRUCTIONS.
C
PRINT 100
READ (*, 200, IOSTAT=ISTAT) A
IF (A .EQ. 'Y' .OR. A .EQ. 'y') CALL HELP()
C
C INITIALISE THE GAME.
C
CALL INIT()
C
C RUN UNTIL GAME IS OVER.
C
10 CONTINUE
CALL TURN(NEXT)
IF (NEXT) GOTO 10
100 FORMAT (' HUNT THE WUMPUS',/,/,' INSTRUCTIONS? (Y/N) ',$)
200 FORMAT (A)
END
C ****************************************************************
INTEGER FUNCTION IADJAC(IFROM)
C
C RETURNS RANDOM ROOM ADJACENT TO IFROM.
C
INTEGER IFROM
INTEGER I
INTEGER IROOMY(20, 3)
COMMON /WORLD/ IROOMY
I = 1 + INT(RAND(0) * 3)
IADJAC = IROOMY(IFROM, I)
END
C ******************************************************************
INTEGER FUNCTION INPUT()
C
C READS PLAYER INPUT (1, 2, OR 3).
C
INTEGER ISTAT
10 CONTINUE
READ (*, 100, IOSTAT=ISTAT) INPUT
IF (ISTAT .NE. 0 .OR. INPUT .LT. 1 .OR. INPUT .GT. 3) THEN
PRINT 200
GOTO 10
END IF
100 FORMAT (I1)
200 FORMAT (' INVALID INPUT. TRY AGAIN: ',$)
END
C ****************************************************************
INTEGER FUNCTION IRANDR()
C
C RETURNS RANDOM EMPTY ROOM.
C
LOGICAL EMPTY
10 CONTINUE
IRANDR = 1 + INT(RAND(0) * 20)
IF (.NOT. EMPTY(IRANDR)) GOTO 10
END
C ****************************************************************
LOGICAL FUNCTION EMPTY(IROOM)
C
C RETURNS .TRUE. IF GIVEN ROOM IS EMPTY.
C
INTEGER IROOM
INTEGER IBATY(2), IPITY(2), IWUMP, IHERO, NARROW
COMMON /STATE/ IBATY, IPITY, IWUMP, IHERO, NARROW
EMPTY = .FALSE.
IF (IROOM .EQ. IHERO .OR. IROOM .EQ. IWUMP .OR.
& IROOM .EQ. IBATY(1) .OR. IROOM .EQ. IBATY(2) .OR.
& IROOM .EQ. IPITY(1) .OR. IROOM .EQ. IPITY(2)) RETURN
EMPTY = .TRUE.
END
C ****************************************************************
SUBROUTINE HELP()
C
C PRINTS INSTRUCTIONS.
C
CHARACTER A
INTEGER ISTAT
PRINT 200
READ (*, 100, IOSTAT=ISTAT) A
PRINT 300
READ (*, 100, IOSTAT=ISTAT) A
PRINT 400
READ (*, 100, IOSTAT=ISTAT) A
PRINT 500
READ (*, 100, IOSTAT=ISTAT) A
100 FORMAT (A)
200 FORMAT (/,' WELCOME TO "HUNT THE WUMPUS"',/,/,
&' THE WUMPUS LIVES IN A CAVE OF 20 ROOMS. EACH ROOM HAS THREE',/,
&' TUNNELS LEADING TO OTHER ROOMS. (LOOK AT A DODECAHEDRON TO',/,
&' SEE HOW THIS WORKS -- IF YOU DON''T KNOW WHAT A DODECAHEDRON',/,
&' IS, ASK SOMEONE.)',/,/,
&' HAZARDS:',/,/,
&2X,'BOTTOMLESS PITS - TWO ROOMS HAVE BOTTOMLESS PITS IN THEM.',/,
&4X,'IF YOU GO THERE, YOU FALL INTO THE PIT (AND LOSE).',/,/,
&2X,'SUPER BATS - TWO OTHER ROOMS HAVE SUPER BATS. IF YOU GO',/,
&4X,'THERE, A BAT GRABS YOU AND TAKES YOU TO SOME OTHER ROOM',/,
&4X,'AT RANDOM. (WHICH MIGHT BE TROUBLESOME)',/,/,
&' PRESS RETURN.',$)
300 FORMAT (/,' WUMPUS:',/,/,
&2X,'THE WUMPUS IS NOT BOTHERED BY THE HAZARDS (HE HAS SUCKER',/,
&2X,'FEET AND IS TOO BIG FOR A BAT TO LIFT). USUALLY HE IS',/,
&2X,'ASLEEP. TWO THINGS WAKE HIM UP: YOUR ENTERING HIS ROOM OR',/,
&2X,'YOUR SHOOTING AN ARROW.',/,/,
&2X,'IF THE WUMPUS WAKES, HE MOVES (P=.75) ONE ROOM OR STAYS',/,
&2X,'STILL (P=.25). AFTER THAT, IF HE IS WHERE YOU ARE, HE EATS',/,
&2X,'YOU UP (AND YOU LOSE).',/,/,
&' PRESS RETURN.',$)
400 FORMAT (/,' YOU:',/,/,
&2X,'EACH TURN YOU MAY MOVE OR SHOOT A CROOKED ARROW.',/,/,
&2X,'MOVING: YOU CAN GO ONE ROOM (THRU ONE TUNNEL).',/,
&2X,'ARROWS: YOU HAVE 5 ARROWS. YOU LOSE WHEN YOU RUN OUT.',/,/,
&2X,'EACH ARROW CAN GO FROM 1 TO 5 ROOMS. YOU AIM BY TELLING',/,
&2X,'THE COMPUTER THE ROOMS YOU WANT THE ARROW TO GO TO.',/,
&2X,'IF THE ARROW CAN''T GO THAT WAY (I.E. NO TUNNEL) IT',/,
&2X,'MOVES AT RAMDOM TO THE NEXT ROOM.',/,/,
&2X,'IF THE ARROW HITS THE WUMPUS, YOU WIN.',/,
&2X,'IF THE ARROW HITS YOU, YOU LOSE.',/,/,
&' PRESS RETURN.',$)
500 FORMAT (/,' WARNINGS:',/,/,
&2X,'WHEN YOU ARE ONE ROOM AWAY FROM WUMPUS OR HAZARD,',/,
&2X,'THE COMPUTER SAYS:',/,/,
&2X,'WUMPUS - "YOU SMELL A WUMPUS!"',/,
&2X,'BAT - "BATS NEARBY!"',/,
&2X,'PIT - "YOU FEEL A DRAFT!"',/,/,
&' PRESS RETURN.',$)
END
C ****************************************************************
SUBROUTINE INIT()
C
C INITIALISES THE GAME.
C
INTEGER IRANDR
INTEGER IBATY(2), IPITY(2), IWUMP, IHERO, NARROW
COMMON /STATE/ IBATY, IPITY, IWUMP, IHERO, NARROW
IBATY(1) = IRANDR()
IBATY(2) = IRANDR()
IPITY(1) = IRANDR()
IPITY(2) = IRANDR()
IWUMP = IRANDR()
IHERO = IRANDR()
NARROW = 5
END
C ****************************************************************
SUBROUTINE MOVE()
C
C MOVES PLAYER.
C
INTEGER IBATY(2), IPITY(2), IWUMP, IHERO, NARROW
INTEGER IROOMY(20, 3)
COMMON /STATE/ IBATY, IPITY, IWUMP, IHERO, NARROW
COMMON /WORLD/ IROOMY
INTEGER IROOM, ISTAT
PRINT 100
10 CONTINUE
READ (*, *, IOSTAT=ISTAT) IROOM
IF (ISTAT .NE. 0 .OR. IROOM .LT. 1 .OR. IROOM .GT. 20) THEN
PRINT 200
GOTO 10
END IF
IF (IROOM .NE. IROOMY(IHERO, 1) .AND.
& IROOM .NE. IROOMY(IHERO, 2) .AND.
& IROOM .NE. IROOMY(IHERO, 3)) THEN
PRINT 200
GOTO 10
END IF
IHERO = IROOM
100 FORMAT (' WHICH ROOM DO YOU WANT TO ENTER? ',$)
200 FORMAT (' INVALID INPUT. TRY AGAIN: ',$)
END
C ****************************************************************
SUBROUTINE SHOOT()
C
C SHOOTS INTO ROOM.
C
C
INTEGER IADJAC
INTEGER IBATY(2), IPITY(2), IWUMP, IHERO, NARROW
INTEGER IROOMY(20, 3)
COMMON /STATE/ IBATY, IPITY, IWUMP, IHERO, NARROW
COMMON /WORLD/ IROOMY
INTEGER IDIRY(5)
INTEGER I, ISTAT, LAST, N, NEXT
PRINT 100
10 CONTINUE
C
C INITIALISE DIRECTION ARRAY.
C
DO 20 I = 1, SIZE(IDIRY)
IDIRY(I) = 0
20 CONTINUE
C
C READ LIST OF ROOMS TO SHOOT INTO.
C
READ (*, 200, IOSTAT=ISTAT) IDIRY
IF (ISTAT .NE. 0) THEN
PRINT 300
GOTO 10
END IF
C
C VALIDATE INPUT.
C
N = 0
DO 30 I = 1, SIZE(IDIRY)
IF (IDIRY(I) .GT. 0) N = I
30 CONTINUE
IF (N .EQ. 0) THEN
PRINT 300
GOTO 10
END IF
IF (IDIRY(1) .EQ. IHERO) THEN
PRINT 400
GOTO 10
END IF
C
C SHOOT ARROW IN UP TO FIVE ROOMS.
C
NARROW = NARROW - 1
LAST = IHERO
DO 40 I = 1, N
NEXT = IDIRY(I)
IF ((NEXT .EQ. LAST) .OR. (NEXT .LT. 1) .OR. (NEXT .GT. 20) .OR.
& (NEXT .NE. IROOMY(LAST, 1) .AND.
& NEXT .NE. IROOMY(LAST, 2) .AND.
& NEXT .NE. IROOMY(LAST, 3))) THEN
NEXT = IADJAC(LAST)
END IF
IF (NEXT .EQ. IHERO) THEN
IHERO = 0
RETURN
END IF
IF (NEXT .EQ. IWUMP) THEN
IWUMP = 0
RETURN
END IF
LAST = NEXT
40 CONTINUE
C
C WAKE UP THE WUMPUS.
C
IF (RAND(0) .LT. 0.75) IWUMP = IADJAC(IWUMP)
100 FORMAT (' ENTER A LIST OF ROOMS TO SHOOT INTO (UP TO 5): ',$)
200 FORMAT (5(I2,1X))
300 FORMAT (' INVALID INPUT. TRY AGAIN: ',$)
400 FORMAT (' YOU HAVE TO AIM INTO AN ADJACENT ROOM, STUPID.')
END
C ****************************************************************
SUBROUTINE TURN(NEXT)
C
C RUNS NEXT TURN.
C
EXTERNAL MOVE, SHOOT
INTEGER INPUT
LOGICAL NEXT
INTEGER IBATY(2), IPITY(2), IWUMP, IHERO, NARROW
INTEGER IROOMY(20, 3)
COMMON /STATE/ IBATY, IPITY, IWUMP, IHERO, NARROW
COMMON /WORLD/ IROOMY
INTEGER I, IROOM, K
NEXT = .FALSE.
IF (IWUMP .EQ. 0) THEN
PRINT 200
RETURN
END IF
IF (IHERO .EQ. IWUMP) THEN
PRINT 300
PRINT 100
RETURN
END IF
IF (IHERO .EQ. 0) THEN
PRINT 400
PRINT 100
RETURN
END IF
IF (NARROW .LT. 1) THEN
PRINT 500
PRINT 100
RETURN
END IF
IF (IHERO .EQ. IPITY(1) .OR. IHERO .EQ. IPITY(2)) THEN
PRINT 600
PRINT 100
RETURN
END IF
IF (IHERO .EQ. IBATY(1) .OR. IHERO .EQ. IBATY(2)) THEN
PRINT 700
IHERO = IRANDR()
END IF
PRINT 800, IHERO
DO 10, I = 3, 1, -1
IROOM = IROOMY(IHERO, I)
IF (IROOM .EQ. IWUMP) PRINT 900
IF (IROOM .EQ. IBATY(1) .OR. IROOM .EQ. IBATY(2)) PRINT 1000
IF (IROOM .EQ. IPITY(1) .OR. IROOM .EQ. IPITY(2)) PRINT 1100
10 CONTINUE
PRINT 1200, NARROW, IROOMY(IHERO, 1), IROOMY(IHERO, 2),
& IROOMY(IHERO, 3)
K = INPUT()
IF (K .EQ. 1) THEN
CALL MOVE()
ELSE IF (K .EQ. 2) THEN
CALL SHOOT()
ELSE IF (K .EQ. 3) THEN
RETURN
END IF
NEXT = .TRUE.
100 FORMAT (' GAME OVER.')
200 FORMAT (' AHA! YOU GOT THE WUMPUS!')
300 FORMAT (' YOU FIND YOURSELF FACE TO FACE WITH THE WUMPUS.',
&' IT EATS YOU WHOLE.')
400 FORMAT (' OUCH! ARROW GOT YOU!')
500 FORMAT (' YOU HAVE RUN OUT OF ARROWS!')
600 FORMAT (' AAAAAAAAAAA! YOU HAVE FALLEN INTO A BOTTOMLESS PIT.')
700 FORMAT (' A BAT HAS CARRIED YOU INTO ANOTHER EMPTY ROOM.')
800 FORMAT (/,' YOU ARE IN ROOM ',I2,'.')
900 FORMAT (' YOU SMELL A WUMPUS!')
1000 FORMAT (' BATS NEARBY!')
1100 FORMAT (' YOUR FEEL A DRAFT!')
1200 FORMAT (' YOU HAVE ',I1,' ARROWS. TUNNELS LEAD TO ',I2,', ',I2,
&' AND ',I2,'.',/,' (1) MOVE (2) SHOOT (3) QUIT: ',$)
END
C ****************************************************************
BLOCK DATA
C
C COMMON VARIABLES:
C
C IBATY - ROOMS OF BATS (2).
C IPITY - ROOMS OF PITS (2).
C IWUMP - ROOM OF WUMPUS.
C IHERO - ROOM OF PLAYER.
C NARROW - NUMBER OF ARROWS LEFT.
C IROOMY - CONNECTIONS BETWEEN ROOMS.
C
INTEGER IBATY(2), IPITY(2), IWUMP, IHERO, NARROW
INTEGER IROOMY(20, 3)
COMMON /STATE/ IBATY, IPITY, IWUMP, IHERO, NARROW
COMMON /WORLD/ IROOMY
DATA IROOMY /2,1,2,3,1,5,6,1,8,2,10,3,12,4,6,15,7,9,11,13,
&5,3,4,5,4,7,8,7,10,9,12,11,14,13,14,17,16,17,18,16,
&8,10,12,14,6,15,17,9,18,11,19,13,20,15,16,20,18,19,20,19/
END| UNIX | Flang/F18 | $ flang -o wumpus wumpus.f |
|---|---|---|
| GNU Fortran | $ gfortran -o wumpus wumpus.f | |
| Intel Fortran Compiler | $ ifort -o wumpus wumpus.f | |
| Win32 | Digital/Compaq Visual Fortran | > fl32.exe wumpus.f /Fe=wumpus.exe |
