Toaru Majutsu no Index Struggle Battle

Toaru Majutsu no Index Struggle Battle (とある魔術の禁書目録（インデックス）頂点決戦（ストラグルバトル）) is an online social game by Mobage, which was released on December 20, 2012, for iOS devices, Android devices, and mobile phones.

Promotion
The game was silently announced by Dengeki on October 7, 2012, 3 days before the release of the 5th Shinyaku Toaru Majutsu no Index light novel volume, and amidst news regarding Toaru Majutsu to Kagaku no Ensemble and the Toaru Majutsu no Index Movie.

On November 22, 2012, advanced registration of the game has opened, and those who have registered early will get a chance to attain a limited Misaka Misuzu card. On December 20, 2012, the game becomes open for the public and rare Christmas-themed cards are shown, as well super rare cards announced to be revealed on December 29.

Serial codes will be released for the game when the Toaru Majutsu no Index Movie is released.

Gameplay
The game is a social game with the motif of collecting the abilities of the characters from the series, with the aim of becoming the strongest in Academy City. There are bosses in the game scenario, as well as raid bosses for the players to cooperate in beating them. There are three types of battles: Force, Thought, and Technique.

Similar to the likes of the PSP game, it also features "talking parts", where the narrative of the story is detailed through the interaction between characters with sprites and text at the bottom that is commonly featured in visual novels.

Main page
On the main page as banners that have main events that yields special offerings if the player joins, such as Christmas and New Year events, and tasks for beginners of the game. The player can get all rewards on their giftbox to accept the rewards.

Basic options
The user can play the game against other people in PVP through the use of cards of the characters. The player can make friends, though if the player wants to befriend a specific person, they have to befriend them outside the game first, before being able to befriend them in-game.

The in-game menu has options for the player to initiate quests, use their stamina, play PVP, or use attack points. The player can initiate quests, which allows them to gain cards and loot, or send out quests on their own to friends. Moreover, the player can also rob others from loot in PVP. When the player collects 6 loots of the same type for a rare card. Furthermore, the player can level up and can give 3 points to either stamina, defense, or attack, at maximum on each level up, as well as 3 points for each friend.

Cards
There are two types of cards: magic side or science side.

The player has a deck, and are given starter cards. The deck can be edited to modify their defense and attack formations. Each character has a cost, to which sum of all character's cost can be less than or equal to the player's attack. The player can level up cards to increase their stats by fusing them with other cards by using the Strengthening option. This is where the rarity of designation upon each card come from. The tiers of rarity are N, R, HR, LR, SR, apparently, there are varying tiers for each tier of rarity, as evidence by Rare cards having a plus sign next to them. The cards can be evolved, under the Evolve option, by fusing 2 cards of the same type, increasing the card's stats and maximum level, but also increases its cost. The Rebirth opinion increases the card's maximum level by fusing it with the same type of cards, up to 5 cards at once.

The illustrations of the cards are taken directly from screenshots of characters that are from both seasons of the Toaru Majutsu no Index anime adaptation that are vectorized, from promotional art drawn in the same way as the rest of the illustrations, as with the case of the Mikoto and Index Christmas-themed cards, as well as light novel artwork. The game also reuses the sprites from the Toaru Majutsu no Index PSP game.

Story
The story tells of a player who has the ability known as Imagine Shadow. A mysterious girl by the name of Usamimi call for the player, and makes use of the player's unique power through of the use Boosters. She enlists the player to become the strongest in Academy City, but she shows her true colors, wanting magic and esper powers herself, breaking the pact between the magic and science, leading to her being targeted by both sides.

It is an original story written by Kamachi Kazuma.