Price: £1.99
★★★★☆

The title might bring to mind 1970s British spy thrillers but The Octagon Theory has little to do with thick-rimmed glasses, expensive suits and unraveling government secrets. Rather, this stylish, minimalist strategy game draws inspiration from Sumo Wrestling, the Japanese sport played by heavy men in loincloths.

As in Sumo, the aim of the game is to push your opponent out of an octagonal ring. You take turns to place pieces on the board. Each piece has a directional arrow associated to it and will push any opponent’s piece that sits adjacent in the indicated direction. In this way it’s possible to shunt your opponent off the edge of the ring, but you risk a counterattack as you do so.

As well as an infinite stock of single directional pieces, you also have a limited stock of special pieces that ‘push’ in two, four or even eight directions. Often matches can hinge on a single move, and knowing when to use these more valuable resources is key to victory.

Scoring is disarmingly simple: your total number of points is equal to the number of pieces you have on the board at any one time. You play for a set number of turns and the player with most points on the board at the end is the winner. The Tron-like aesthetic gives the game a futuristic feel, although the core rules feel ancient and dependable, like a distant, forgotten cousin to Othello or Checkers (and, while the concept might not be quite so ancient as those boardgames, designer Theron Daniel Huffman copyrighted the idea in 1994).

Boards come in three different sizes depending on how long you want a match to last, and while it’s possible to play a two-player match by passing your device back and forth between both of you, there’s no online multiplayer as yet. A choice of different AI opponents allows you to set the temperament of your computer-controlled rival, but it will take a while before the full range of strategies available blossoms in your mind.

A smart iOS title with weighty strategic depth, The Octagon Theory is like a gem of a boardgame uncovered one day while rooting around in your grandparents’ loft. Its Zen-like, if urgent rhythms may be a far cry from the Japanese sport from which it draws influence, but underneath the serene style there’s a sharp tactical game of equal ferocity.