Gaiden Volume - Practical War Game

is a gaiden volume of the  of the  No Game No Life  series, published on December 23, 2016. It was released in two different editions, the special  limited edition that was bundled with a Sora Nendoroid, and the regular edition. Practical War Game has not been translated in English officially, however NekoPrism is working on an English Fan-Translation currently. Progress on it can be viewed on both her profile and Reddit page.

Story Details
Synopsis= Before the creation of the world Disboardーwhere everything is determined by games, Humanity wasn't the only one who tried to end the Great Warーa war that tore the stars apart and was dismissed as a game. The rules were slightly different though, as the future that a certain Elf had envisionedー"If you kill all the stars and remain standing, you win". In other words―"Anything goes!" In addition to an all-new novella about "Another End of the War" as envisioned by Think Nirvalen, this is a splendid special edition that includes the hot and loose short stories included in the bonus features of the anime! "Now―let the war begin~"

The Gaiden volume covers six short stories including different characters about their exploits during different periods in time.
 * -|Summary=

Abstract War Game
As Sora plays chess with Fiel Nirvalen to test the effect of her Magic after the two "joined" the Commonwealth of Elkia, they begin to talk about Nina Clive and Think Nirvalenーthe two magic casters who were given the title of Corolla, with abilities superior to their descendant.

Practical War Game
The story never told about the game of Think Nirvalen, Nina Clive against Lóni Drauvnil. How the former taste her first defeat in the device of latter, the exact relationship between two Corollas, the creation of "Protections", and the end of the war in their own sight...

Three Times to Repeat the Game
As she plays a desperate game against Sora to prove the fact she isn't an idiot, and the Immanity king had revealed his trick in the sleeve, a horrible incident occurs when Stephanie Dola finds herself paying a risky price to play on equal terms with Sora.

Is on the Card or Peach Flush
Chlammy Zell reminiscence her life from an incident that occurred a few months before her defeat at the hand of Kuhaku and their coronation, which pushed Fiel to rebel against Elven Gard's corrupted hierarchy. After numerous events taken place, Chlammy has made use of Sora's trick she learned from his memories to take her revenge while the duo takes step toward their plans by tying up a loose end.

Highcard All Raise Vol. 1
During the Great War, the Flügel committed many atrocities in the name of Artosh, their creator and the God of War. However, Raphael and Azril noted the mightiest figure in the world rarely smiled ever since slaying Hartyrave himself, except being challenged by their youngest sister, Jibril. As the Valkyries continue their daily battle, Jibril decided to challenge a Dragonia by herself.

Highcard All Raise Vol. 2
After suffering 5 defeats in the hands of the White Dragon Lichtengärte, Jibril gain the habit of writing a diary and learned elf language in order to defeat the dragon. Meanwhile, Azril decided to stop the extra unit by force if necessary. Looking at the actions, decisions, and accomplishments of his creations, Artosh slowly remembers the true meaning behind the extra unit...

Chapters

 * Abstract War Game
 * Practical War Game
 * Threefold Levitation
 * One Pair or Heart Straight Flush
 * High-Card All Raise Part 1
 * High-Card All Raise Part 2

New Characters

 * Nina Clive
 * Lóni Drauvnil
 * Asëa Aranion
 * Hartyrave
 * Lichtengärte

Illustrations
Gaiden Volume - Practical War Game