Colossal Cave Adventure

References

1. ^Eric S. Raymond's history in the Open Adventure repository dates Will Crowther's earliest version to 1976 on a PDP-10 at Bolt, Beranek and Newman, and Don Woods's expanded 350-point version to June 3, 1977 at the Stanford AI Lab; Crowther and Woods's own line ended with the 430-point Adventure 2.5 in 1995.Code notesOpen Adventure 1.22
   How we know

   16The very first version was released by Crowther in 1976, in FORTRAN on
   

   24released on a PDP-10 at the Stanford AI Lab by Don Woods on June 3rd,
   251977 (some sources erroneously say 1976). That version is sometimes
   26known as 350-point Adventure.
   

   30in the 1995 release of Adventure 2.5, also known as 430-point Adventure
   

   The quote matches our archived copy.

   Checked by a second AI model, 2026-10-22.

   In the claim ledger

2. ^Open Adventure, the C port of Crowther and Woods's Adventure 2.5 (1995), refuses any input of more than two words, answering “Please stick to 1- and 2-word commands.” It matches each word against its vocabulary on the first five letters only, ignoring case, and the instructions it shows a player who asks for them say to type “ne” for northeast, since “northeast” would read as “north”.CodeOpen Adventure 1.22revised
   How we know

   567		if (word_count(input) > 2) {
   

   2920- TWO_WORDS: 'Please stick to 1- and 2-word commands.'
   

   22#define TOKLEN 5          // # outputting characters in a token */
   

   401			if (strncasecmp(word, objects[i].words.strs[j],
   402			                TOKLEN) == 0) {
   

   384			if (strncasecmp(word, motions[i].words.strs[j],
   385			                TOKLEN) == 0 &&
   

   2862      you that I look at only the first five letters of each word, so you'll
   2863      have to enter "northeast" as "ne" to distinguish it from "north".
   

   Checked against the evidence by its author, an AI model, 2026-10-22.

   Revised after a check by a second AI model, 2026-10-22.

   In the claim ledger

3. ^In Open Adventure (Adventure 2.5) the lamp's limit starts at 330 turns, or 1,000 if the player answers yes to “Would you like instructions?” Once per command, while the lamp is lit, the limit drops by 1; the check runs at the end of the cave-closing check, which returns before it on the turn the cave starts to close and the turn it closes. At 30 or below, fresh batteries in the room or carried, with the lamp also here, are used up and add 2,500; otherwise the game warns once. At 0 the lamp goes dark.CodeOpen Adventure 1.22
   How we know

   32#define BATTERYLIFE 2500  // turn limit increment from batteries
   

   26    .loc = LOC_START,       .limit = GAMELIMIT,      .foobar = WORD_EMPTY,
   

   1547			game.limit = NOVICELIMIT;
   

   2935- WELCOME_YOU: 'Welcome to Adventure!!  Would you like instructions?'
   

   874	if (game.objects[LAMP].prop == LAMP_BRIGHT) {
   875		--game.limit;
   

   900			game.limit += BATTERYLIFE;
   

   915		game.objects[LAMP].prop = LAMP_DARK;
   

   1044	lampcheck();
   

   1326			if (closecheck()) {
   

   Checked against the evidence by its author, an AI model, 2026-10-22.

   Checked by a second AI model, 2026-10-22.

   In the claim ledger

4. ^Open Adventure (Adventure 2.5) refuses to take an object while 7 are already carried: “You can't carry anything more. You'll have to drop something first.” The bird doesn't count, a fix of the original's counting the caged bird as two items.CodeOpen Adventure 1.22
   How we know

   25#define INVLIMIT 7        // inventory limit (# of objects)
   

   386	if (game.holdng >= INVLIMIT) {
   387		rspeak(CARRY_LIMIT);
   

   2945- CARRY_LIMIT: 'You can''t carry anything more.  You''ll have to drop something first.'
   

   672		if (object != BIRD) {
   673			++game.holdng;
   

   57* The caged bird used to be counted as two items in your inventory.
   

   Checked against the evidence by its author, an AI model, 2026-10-22.

   Checked by a second AI model, 2026-10-22.

   In the claim ledger

5. ^Open Adventure's score routine (Adventure 2.5) tallies 430 points in its comment, 298 of them for treasures (computed: 60 + 14 + 224). Each treasure gives 2 points once found, and the rest of its worth (12 for treasures numbered before the chest, 14 for the chest, 16 for those after it) while it lies in the building in its found state, so a broken one doesn't pay.CodeOpen Adventure 1.22
   How we know

   33	 *                                       TOTAL:   430
   

   First tally up the treasures. Must be in building and not broken.

   55			if (game.objects[i].place == LOC_BUILDING &&
   56			    OBJECT_IS_FOUND(i)) {
   57				score += k - 2;
   

   Checked against the evidence by its author, an AI model, 2026-10-22.

   Checked by a second AI model, 2026-10-22.

   In the claim ledger

6. ^In Open Adventure (Adventure 2.5), each dwarf that was already in the hero's location before the dwarves moved throws a knife, which hits if a roll of 0–999 is below 95 × (dflag − 2). The first volley always misses, at dflag 2; it raises dflag to 3, so each later knife hits 9.5% of the time (computed). Feeding a dwarf while food is here adds 2 to dflag, so 28.5% after one feeding (computed). Any hit kills the hero.CodeOpen Adventure 1.22
   How we know

   313	/* Dwarves move.  Return true if player survives, false if he dies. */
   

   442			if (randrange(1000) < 95 * (game.dflag - 2)) {
   

   457	if (game.dflag == 2) {
   458		game.dflag = 3;
   

   472	game.oldlc2 = game.loc;
   473	return false;
   

   3 A knife has been thrown (first set always misses) 3+

   717		if (HERE(FOOD)) {
   718			game.dflag += 2;
   

   Checked against the evidence by its author, an AI model, 2026-10-22.

   Checked by a second AI model, 2026-10-22.

   In the claim ledger