Elements is a strategic attribute that was in game since first Epic Battle Fantasy, but it was named and specified in Epic Battle Fantasy 2 along with addition of Bestiary, and later expanded in EBF 3 and EBF 4.
Elemental strengths and weaknesses can be identified by using Scan on an enemy during battle. The strengths and weaknesses of scanned foes can then be seen at any time by hovering the mouse over "?", which appears next to all scanned enemies. When outside of battle resistances can be checked using the Bestiary.
Using an attack with the element oponent is weak to and avoid using attacks he resists is the simplest way to dish out maximum amount of damage, when equiping armors and weapons that increase party's resistances to elements enemy is using in his attacks will greatly improve their survivability.
Example of resistances screen. (EBF4)