Wizardry: Proving Grounds of the Mad Overlord is the first game in the Wizardry series of role-playing video games. It was developed by Andrew Greenberg and Robert Woodhead. In 1980, Norman Sirotek formed Sir-tech Software, Inc. and launched a Beta version of the product at the 1980 Boston Computer Convention. The final version of the game was released in 1981.

The game was one of the first Dungeons & Dragons-style role-playing games to be written for computer play, and the first such game to offer color graphics. It was also the first true party-based role-playing video game.

The game eventually ended up as the first of a trilogy that also included Wizardry II: The Knight of Diamonds and Wizardry III: Legacy of Llylgamyn.Proving Grounds needs to be completed in order to create a party that could play in the remainder of the trilogy.

Starting in the town, the player creates a party of up to six characters from an assortment of five possible races (Humans, Elves, Dwarves, Gnomes, Hobbits), three alignments (Good, Neutral, Evil), and four basic classes (Fighter, Priest, Mage, Thief). There are also four elite classes (Bishop: priest and mage spells; Samurai: fighter with mage spells; Lord: fighter with priest spells, and Ninja: fighter with thief abilities). Characters can be changed to an elite class after meeting the stat requirements. Priests typically cast healing spells, while Mages cast damage spells. Bishops, being a combination of the two, learn both sets of spells but at a reduced rate. Good and evil characters normally cannot be assigned to the same party. However, you can drop party members off at the stairs leading out of the maze, then go back out and get a character of the opposite alignment, then pick up the ones you dropped off, thus making it possible to have both good and evil characters.

After equipping the characters with basic armor and weaponry, the party then descends into the dungeon below Trebor's castle. This consists of a maze of ten levels, each progressively more challenging than the last.

The style of play employed in this game has come to be termed a dungeon crawl. The goal, as in most subsequent role-playing video games, is to find treasure including ever more potent items, gain levels of experience by killing monsters, then face the evil arch-wizard Werdna on the bottom level and retrieve a powerful amulet. The goal of most levels is to find the elevator or stairs going down to the next level without being killed in the process.

The graphics are extremely simple by today's standards; most of the screen is occupied by text, with about 10% devoted to a first-person view of the dungeon maze using high-resolution line graphics. By the standards of the day, however, the graphics were a step forward from the text-only games that had been far more common. When monsters are encountered, the dungeon maze disappears, replaced by a picture of one of the monsters. Combat is against from 1 to 4 groups of monsters. The game's lack of an automap feature, which had not been invented at the time of its release, practically forces the player to draw the map for each level on a piece of graph paper as he walks through the dungeon maze, step by step - failing to do this often results in becoming permanently lost, as there are many locations in the maze that have a permanent "Darkness" spell upon the square (making the player walk blindly) or a "Teleport" spell sending the player to a new location. A magic spell can be used to determine the current location of the party, and at higher levels there is a teleport spell that can be used to quickly transition between the maze levels. Care is necessary when teleporting as the player must enter both the level and coordinates to teleport to (the number of steps north, south, east, or west from his current location) and it is easily possible to land in a trap or solid stone, ending the game. The original releases of Wizardry also do not announce that the player has teleported and play resumes as if one step forward was taken.

The spells in Wizardry have nonsensical names (eg. Malor is the teleport spell) and it is entirely up to the player to figure out what each one does. Some spells have negative effects, for example reducing the party's HP during combat.

The game has unforgiving difficulty as players cannot save their progress within the dungeon and must navigate their way back outside to the castle first. If the entire party is killed or teleports into stone, play also resumes there and your party must go back through the dungeon starting with Level 1. Later Wizardry games made it easier by restarting at the point in the dungeon where the player died. It can take hundreds of hours to finish the game.

Wizardry saves the player's party and game progress onto a scenario disk. After booting, a new one may be created with a blank floppy disk or an existing one used. Completion of Proving Ground of the Mad Overlord is necessary to play the sequels Wizardry II and III since they require the characters from the first game to be imported from a scenario disk.

Cheats

At the easiest level is the ability to manufacture gold. Players can create new characters, pool their gold to one of them, then delete the others and repeat the process.

Another more common way to manipulate the game is through using a hex-editor. By altering the values stored at certain locations within a file, it is possible to alter many facets of the game, including the amount of gold (to buy better items), the experience points, character level or trait, even items in the player's possession.

On the Apple IIe version, you can gain infinite levels by removing the game disk and inserting a blank disk into the drive when you rest at the Inn. It gets a little slower to level after each leveling, but it is very fast at the beginning. When you get to around level 300, it takes about two minutes to gain a level. Ninjas at this level frequently get critical hits and can one shot anything in the dungeon.

There is an Easter egg that can be quite helpful in winning the game. Members of the Bishop class are capable of "identifying" unknown objects in a player's inventory, but the inventory list is only 8 items long. If a Bishop attempts to identify the 9th item and is successful, he receives one hundred million experience points. By then repeatedly resting at the Adventurers' Inn, the player's level (including hit points, spell-casting ability, etc.) can be raised to extreme levels. Three Bishops going through the maze after identifying #9 are all but invulnerable.

Another lesser known cheat, available on the Apple II version (and which may have been available on other platforms), also involves the Bishop. If the Bishop is commanded to identify an item number, but the letter "s" is hit instead, the character below the Bishop in the roster is given one hundred million experience. Identifying the letter "j" gives the character below the bishop one hundred million gold.

According to co-author Robert Woodhead, the "identify cheats" were actually a bug. The line of code checking for a valid key from "1" to "8" read 'if (ch >= "1") or (ch <= "8")'; the "or" should have been an "and". If the identify succeeded, a bit would get flipped in an indexed data structure, and bounds-checking was disabled in the game in order to get it to fit into the 48k of memory available. Typing "9" would flip a bit in the experience-point data element, and typing other keys would have a variety of effects, including crashing the game, and even temporarily changing the current dungeon level. Woodhead recalls getting a letter from a player that listed the apparent effects of every typable key on an Apple II keyboard.

When the IBM PC version of the game was released, the bug was declared to be a feature, and deliberately included.