Robot Dungeon 2121 - ABBUC 2021 Software Contest by Anschuetz/Weisgerber/Anschuetz

rra · November 17, 2021

Atari 8-bit version: Robot Dungeon 2121.xex

Atari 5200 version: Robot Dungeon 2121.rom

Attached are the Atari 8bit and 5200 versions of Robot Dungeon 2121 that was entered in the ABBUC 2021 software contest.

The original BASIC version of Robot Dungeon was published in the "disk edition" of Antic Magazine in November 1985 and available here: http://www.atarimania.com/game-atari-400-800-xl-xe-robot-dungeon_4411.html

Robot Dungeon 2121 is known for its deadly robots, electrified walls, and teleports. Rumor has it that no one has ever escaped alive! Nobody knows for sure, but the best estimations are that Robot Dungeon is comprised of multiple levels of rooms, arranged in a maze. Each level has only one way out. The object of the game is to traverse from the lower-left room of each level to the upper-right room, all while amassing as many lives and as high a score as possible. Upon reaching the upper-right room on each level, you must touch the staircase and you will then proceed automatically to leave the level following a cut-scene. The next level of the maze will have more rooms, so get ready for more challenges trying to find the escape route!

Throughout Robot Dungeon 2121 there are various treasures and traps which with you must be acquainted with. The most abundant of these figures is the symbol of “LIFE”. (It looks like a sideways figure eight). Touching this symbol will give you an extra life. You lose a life every time you touch a robot or touch a wall. It is very important to get the symbol of “LIFE” in each room or you will have a very short adventure!

A symbol closely related to the symbol of “LIFE” is the “CHEST”. Within the “TREASURE CHEST” is 5,000 points. Needless to say, don’t pass up many of these!

Another symbol is the “COIN”. This pile of coins is worth 200 points! Akin to the “COIN” is the “DIAMOND”, which is worth 1000 points!

Perhaps the most useful symbol is the deadly “KILL ALL” robot zapper. This symbol looks like a zig-zag line and kills every robot in a room when touched!

Something to definitely stay away from are the dreaded “WARP ROOM 1” symbols. These are shaped like concentric ovals which will bring you back to the first room of the level which you are on! Stay away from these at all costs!

You are not defenseless as you wander Robot Dungeon 2121. You are equipped with a pistol which can be aimed in any direction. You can shoot up to two laser bullets at a time. To shoot, point your joystick in a direction and press the fire button. The killing of each blue robot is worth 100 points. Note that in every room there is at least one odd-colored robot who cannot be killed except for with the “KILL ALL” robot zapper symbol.

You will note that as you pick up symbols, they are gone forever but robots are resurrected each time you enter or reenter a room. When you lose all of your lives, your game is over.

Until you are really good at the game, start with small-sized mazes like 2x2 or 3x3. You also really need to use the map to see which way to traverse the maze and get to the exit on each level. Remember, there is only one way out, so you will be wasting time and lives if you don’t follow the most efficient route through the rooms in the level. Be sure to get to the “KILL ALL” robot zapper symbol in rooms that have them to kill all of the robots at once. Avoid the “WARP ROOM 1” symbol when you see it or you will go all the way back to the beginning room of the level.

We hope that you enjoy this game!

Robert Anschuetz (@rra)

Eric Anschuetz (@eea)

John Wesigerber (@jjw)

rra · November 17, 2021

The original BASIC version of Robot Dungeon was written in 1984.

Here is a little background about the original game of Robot Dungeon:

Robot Dungeon features a hexagonal maze generation game that borrows heavily from game elements of the arcade game Berzerk, as well as Adventure for the Atari 2600. John Weisgerber discovered a BASIC maze-generating algorithm he read in the Ypsilanti High School library in the June 1981 issue of Creative Computing in an article called “Bee Amazed.” The “Bee Amazed” algorithm generated a maze with hexagonal rooms that when pieced together looked like a honeycomb, with the entry point in the lower-left corner of the maze, and a single exit point at the upper-right corner of the maze.

Each room in the generated maze has 1 to 6 exits leading to adjacent rooms. John used the basis of this algorithm to create a maze generator at the heart of the game. Instead of representing each room as a six-sided hexagon, each room is represented as a rectangular shape with the two potential doors on both the top of each room, two potential doors on the bottom of each room, and one potential door on each on the left and right sides of each room. Therefore, a total of 6 potential doors in each room corresponded to the 6 sides of a hexagon that was part of the maze. The rooms fit together like staggered puzzle pieces. When you exit a door in the upper right of one room, you enter the door in the lower left of the room above.

Robot Dungeon was a really long game for the player to complete. There were three levels of 400 rooms, for a total of 1200 rooms. To reward the player, the A/W/A Team actually programmed cut-scenes at the end of each level with humorous cartoons much like the Pac-Man intermissions. Besides the cut scenes, the programming of this game provided two additional advanced features for a BASIC game. The game offered a “pause” feature and it also provided an “auto save” feature.

The robot movement algorithm was written so that with each iteration of the main processing loop, the robots compared their location to the location of the player and headed toward him. The robots were large redefined characters. The main player was a Player/Missile graphic, as was the shot that the main player could shoot at the monsters.

A separate maze generation program was written to accompany the main program. This needed to be run to create a maze, prior to being able to start the game. The maze could be saved to either cassette or disk. When we wrote Robot Dungeon, they hadn’t yet bought a disk drive. Knowing that there was a limitation of filename length in Atari DOS 2.0, but not knowing if it was 8 characters or 6 characters, the A/W/A Team instructed the player to name the file as “DUNJIN.DAT” instead of “DUNGEON.DAT” just to be safe.

In order to remember the contents of each of 1200 rooms, a novel technique was developed. By using just one 8-bit byte for each room, individual bits represented which of the treasures or obstacles were in the room. This saved up to eight times the memory a traditional technique would have used. This game was also pretty buggy. Because the characters were jumping around, the algorithm for computing whether a missile hit a monster was not always accurate and the missile would sometimes just pass through the monster. Another bug would occasionally allow the player to go right through a wall and be trapped outside the playfield. This was because the comparison of a player collision with a wall or door was too slow to run every loop. One day, Eric and Robert received a phone call from Antic magazine where a game evaluator was stuck outside of a wall and asked what to do! The good news with that phone call was that it was a positive indication that the game was being considered for publication. Ultimately, it was published in a “Add-On Disk” edition that provided a floppy disk with the magazine to avoid typing in the complete program.

Attached is some correspondence from Antic magazine:

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