Dungeon Magic: Sword of the Elements

Dungeon Magic: Sword of the Elements is a first-person RPG (similar in vein to Bard's Tale and the various SSI D&D games) produced by Taito in 1989, and programmed by Natsume for the Nintendo Entertainment System.

One of the interesting aspects of the game was a magic system where a caster could combine runes from various elements to form new magic spells.

Each element had three unique runes, which allowed for 125 different spells. Unfortunately, many of those "different spells" are actually just fireball spells or curative effects. This game had no "magic point" system, so some spells drained the player's hit points instead.

Source: Wikipedia, "Dungeon Magic: Sword of the Elements", available under the CC-BY-SA License.