- Main article: Battle system of Hyperdimension Neptunia mk2
The battle system is turn-based by unit, where each character's turn comes based on their speed. Characters spend AP to attack enemies or use an item. When executing Skills, they expend both AP and SP.
Players can move characters in a limited distance around the battlefield. Character position plays as an important aspect during battle as it affects the area of reach of a character or enemy's attack. The player can also escape a battle if a character is in the edge of the battlefield and has sufficient Luck and Agility.
The character can perform various skills, including utilizing support and offensive skills, inflicting status ailments, or performing combo attacks and EX skills.
- Main article: Chirper
The Chirper acts as a communication system in each landmass, where the player can engage with avatars of characters called 'Gamipics'. Communicating with certain Gamipics may trigger events that may also reward the player with items or increase in Lily Ranks.
While in a dungeon, the player can perform various actions, mainly Treasure Search and Symbol Attacks. Treasure Search is a universal skill that allows the player to find the hidden treasure in a section of the dungeon. When the party leader utilizes Treasure Search near the hidden treasure, it becomes visible and available for pick-up. Symbol Attack allows the player to take advantage of an enemy. When the character hits the enemy from behind, the player gets the first turn of the battle. When the characters' levels are too high for the enemy, a Symbol Attack simply makes the enemy disappear.
Unlike Hyperdimension Neptunia, there is no random encounter in Hyperdimension Neptunia mk2. All enemies inside the dungeon are visible and can be avoided or engaged in battle. Enemies respawn when the player exits the dungeon or uses a Forbidden Twig.
- Main article: Item Development
Item Development, also called Item Synthesis, allows the player to use Product Proposals and materials to create items ranging from consumables to armors. Certain Product Proposals require a certain partners and Lily Ranks to be able to synthesize it to items.
- Main article: Lily Rank
Lily Rank is a gameplay mechanic in Hyperdimension Neptunia mk2 that measures Nepgear's friendship and trust between her companions. Lily Rank may affect the story and may also unlock certain skills. It may also be one of the requirements for synthesizing an item.
- Main article: Share
Share is a vital mechanic in Hyperdimension Neptunia mk2. Shares are distributed through capital cities of a nation and surrounding cities that accumulates into global shares for a major division of a shareholder. The distribution of share affects the storyline and the balance of power between CPUs.
The world map can be seen outside a dungeon, which features cities and dungeons. Locations can be unlocked by advancing through the main storyline or by installing DLCs.