Conquests of Camelot: The Search for the Grail is a graphic adventure by Sierra On-Line, released in 1990 for PC, Amiga, and Atari ST.
The game was written and designed by Christy Marx. It's set in medieval Arthurian mythology, with Arthur, Launcelot, Gawaine, and Galahad searching for the Holy Grail, a quest that will take our hero to Jerusalem.
Some technological choices are strange, considering the game was released in 1990. One year before, adventure game fans had the chance to try Indiana Jones And The Last Crusade, with 256 colors VGA graphics and a verb-based, mouse-driven interface. Instead, Conquests of Camelot uses the Sierra AGI engine, like King's Quest III: To Heir is Human or Leisure Suit Larry in the Land of the Lounge Lizards. This means it has a mix of point-and-click and text parser: you move the hero around the screen and examine objects with the mouse, but when you want to perform an action, you have to type (e.g., "take clothes"). The graphics are amazingly drawn, but the colors are limited to 16, basically EGA graphics on all platforms. Such a pity. But the bad news ends here. Because Conquests of Camelot is an excellent adventure. The plot is well written, and most importantly, instead of being made almost entirely by the usual inventory-based puzzles (like 90% of the graphic adventures out there), you have to talk with people, solve riddles, succeed in small mini-games, and more. You can also finish the game differently; completing all the quests is optional.
In short, don't let the game scare you with its strange color palette. Conquests of Camelot is a gratifying adventure that everyone should try. Oh, and remember to buy the full game on GOG by following the link on the top right.