"Crystals of Arborea is a medieval fantasy role-playing video game developed and published by Silmarils, and released in 1990 for the Amiga, Atari ST and DOS. The game is a precursor to the Ishar trilogy, a series also produced by Silmarils, and together they were re-distributed as the Ishar Compilation in 2009.
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The player assumes the role of Jarel, the last Prince of the Sham-nirs, an elf-like species that inhabits Arborea. Gameplay centres on locating the four crystals, restoring them to their corresponding temples, before defeating Mogroth, the deity of chaos. To accomplish this, the player must form a party of up to six allies, such as wizards, fighters and rangers, each with different strengths and weaknesses. Using both a 3D perspective and a 2D map of the island, players can divide their forces and direct them to perform reconnaissance of a given area. Clues as to the locations of the crystals can be obtained from certain neutral non-player characters, but only if the player is able to answer their riddles or solve puzzles. According to Silmarils, there are approximately 16,000 locations to explore, though not all need to be visited in order to obtain the crystals and restore order.
Should the allies happen upon aggressive creatures or Mogroth's forces, the perspective switches to a 2D grid system. Each character is represented on the grid, but must be positioned so that they have a clear line of sight to their target before they can attack. Rangers and wizards both have the greatest line of sight, whereas swordsmen can only attack if adjacent to their opponent. Prior to obtaining the final crystal, players must battle Mogroth via the grid system. If victorious, Jarel is able to place the last crystal in position and ultimately purge the island of chaos."
Source: Wikipedia, "Crystals_of_Arborea," available under the CC-BY-SA License.