At the end of the last millennium, the board game market was dominated by a certain Dr Reiner Knizia. Within a brief three-year period, Reiner released such classics as Through the Desert (1998), Samurai (1998), Ra (1999), Lost Cities (1999) and Battle Line (2000). All of these games were massive hits and have since been converted to digital platforms. Kicking off this purple patch was the 1997 release of Tigris & Euphrates, for many, the apex of Mr Knizier’s creativity.

Tigris & Euphrates is an abstract civ-building game with heaps of the kind of in-your-face conflict that you rarely see in modern-day euro games. Something else that you should know about Dr Knizia is that he likes nothing more than to tinker with his designs. Indeed, these variations on a theme can exasperate even the most diehard of his fans, who yearn for a return to the good old days of original, demanding games.

So, twenty years after riding a tyre down river Euphrates, Knizia has seen fit to release a sister game entitled Yellow & Yangtze (brought to digital by the fine folks at Dire Wolf Digital, of Raiders of the North Sea fame).

Both games see players competing for points. In Yellow & Yangtze the four areas of influence are: farming, trading, military strength, and administration. However, each player’s final score will be the sphere with the lowest total. The twist is one seen in many of Knizia’s games and it prevents players from gunning for a lopsided strategy.

It also makes thematic sense; there is no point having a massive military force if you haven’t got the resources to feed your soldiers. Players can also earn gold, which is allocated to improve their lowest scoring sphere at the end.

Each player begins the game with a set of different coloured leaders: Governor, Soldier, Farmer, Trader, and Artisan, and a random hand of tiles. The board shows the two eponymous rivers and seven warring cities, each with their own black governor tile. In a move away from T&E, this time the map is divided into hexagons rather than squares.

On each turn players can perform up to two actions. A quick tap will toggle between your leaders and tiles, and the first thing that you will want to do is to drag a leader into play. Leaders must be placed next to a black tile, and doing so will create your first state, defined as a leader with one or more linked tiles. Now, that leader can start you on the path to victory.

Place a tile matching the leader’s colour in the same state and you will earn a point in the corresponding area of influence. Some tiles have their own special rules; the blue farming tiles are limited to placement on rivers, but you can place all of them for just one action. Place a green commercial tile and you can choose a tile from the market, rather than drawing blindly.

One key difference from Tigris & Euphrates is that the building of monuments has been replaced with pagodas. Pagodas are easier to build; just place a triangle of three tiles of the same colour and a pagoda will magically appear. The disadvantages are that they have a lower point-scoring potential and they are not permanent. There can only ever be a maximum of two pagodas of the same colour in play at any one time. As soon as someone builds a third then they must also remove one of the two previously placed form the map.

Yellow & Yangtze is a clever, clever game

There are also more direct ways of messing with your opponent; namely revolts and wars. A revolt is triggered when two like-coloured leaders end up in the same state. The winner is decided by how many black governor tiles each leader is adjacent to, and this total can be boosted by playing extra black tiles directly from your hand.

Wars are initiated when the placement of a tile causes two states to join together that have opposing leaders of the same colour. This time strength is determined by the use of red military tiles. Victory results in points for each opposition leader that was defeated. Losers have to remove their defeated leaders and tiles from the board.

Wars can be very chaotic affairs (as you can tell from our best mobile war games list). A leader will put loyalty to the state before their allegiance to you, so you will sometimes have your leaders on different sides in the same battle. Then, you have the tricky decision of deciding which side to support.

Even neutral players can add supporting tiles to the battle to try and manipulate the outcome. Overall, the stakes in Yellow & Yangtze are lower, there are fewer points on offer, and losing doesn’t feel so harsh. This does mean that conflict is frequent, making the game feel more dynamic.

There are a couple of extra bonus actions to mention. Two green tiles can be discarded to build a new pagoda in an already prepared area. Whereas, two blue tiles can be discarded to initiate a peasant’s riot, leading to a tile being removed permanently from play. Even those leaders that are yet to be placed now have a use. They do not just sit on the sidelines, instead lending their strength in conflicts or reducing the cost of bonus actions.

At first, distinguishing between symbols and colours feels a little counter-intuitive. The colours signify different things depending on the context. Red, for instance, could represent your military leader, soldiers, or swords. In most games you select a colour to play, but here you select a symbol such as a lion or an archer or, wait for it, a pot.

Playing as the pot is the equivalent of being lumbered with the iron in Monopoly. Far more serious is that the solo game has an annoying tendency to freeze during wars. I’m sure that this is an issue that will be addressed shortly, but it may be worth holding back until the inevitable update hits the store.

In the meantime, if you fancy checking out a bunch of other excellent entries, we’ve put together the best digital board games on mobile in a separate list.

The interface is simple and instinctive and the graphics bright and bold, although the map looks a little washed out. Watching your lavish pagoda spring into existence is a real feel good moment. There are plenty of options, too, including pass and play, online, and a solo campaign mode. The nine-stage campaign is cleverly realised, with its own special rules and victory conditions. All the stages are linked in an overarching story, giving new players the chance to hone their skills against challenging AI opponents.

Yellow & Yangtze is a clever, clever game. On the surface, it looks fairly straightforward and old-fashioned. The random tile draw may give the impression of a game with quite a large element of luck. The relentless conflict will have Care Bear gamers scurrying for The Kingdom of Caring. However, it is a design that has stood the test of time and offers just as much enjoyment today as the original game did over twenty years ago.