Monster Call is an ability exclusive to Hyperdimension Neptunia. It allows the player to summon monsters inside a dungeon.
Only certain characters have this ability. When the ability is utilized, the character takes out a bell and rings it, summoning waves of monsters for the player to battle. The battle will usually last 2 to 4 waves. If the player wins the battle, the player will be granted an allotted distance to transverse with no monster encounters.
If the monster bell is used on a monster rune (a dark, glowing rune on the ground), it will summon a Clione. Unlike using Monster Call outside the monster rune, the player will not be granted a distance to travel with no monster encounters.