伊苏：失落的古代

The player controls Adol on a game field viewed from a top-down perspective . As he travels on the main field and explores dungeons, Adol encounters numerous roaming enemies, which he must battle in order to progress. Combat in Ys is rather different from other games of the era, which either had turn-based battles or a manually activated sword. Ys instead features a battle system where fighters automatically attack when walking into their enemies off-center. When one fighter comes into contact with an enemy, damage can be sustained on both sides if both combatants are facing each other. Attacking straight-on causes the attacker the most damage to himself, but clipping the edge of the defender causes the attacked fighter to take most or all of the damage. If one fighter contacts the enemy's side or back, only the attacked fighter will sustain damage. This combat system was created with accessibility in mind. This "bump attack" system has become one of the series' defining features. Falcom staff have compared this style of gameplay to the enjoyment of popping air bubble sheets, in the sense that it took the tedious task of level-grinding and turned it into something similar to a high-score -based arcade video game . According to Games TM and John Szczepaniak of Retro Gamer and The Escapist , "repetition of the act was pleasurable as you developed a psychological rhythm and, even in the event of backtracking, progress was always swift since the player never needed to stop moving". Another feature that has been used in nearly every Ys title since the original is the recharging health mechanism, which had previously been used in the Hydlide series. Recharging health has since become a common mechanism used in many video games today.