G@mebox author Marco Klasmeyer writes about the game:

Introduction:

Two large rivers meander their way from the mountains down to the valley. Only the fields the rivers cross bring in a return for their owners. These yields are needed to build fincas and haziendas. Thus, everyone tries to place his farmers (campesinos) in a way that they stand on those fields which they can harvest. The campesinos are tough! Foreign campesinos are just chased away from the valuable fields. Dams are built and the rivers are diverted. This dries the fields that have just been watered and arid fields suddenly become productive.

Description:

In Dos Rios the players take the role of farmers somewhere in South America, who try to water their fields and claims with the rare water of two rivers. Each player has six campesinos (farm workers) who maintain the fields. But they can also attack their opponents and occupy other fields or dam up the river and hence force it into a new river bed to water other fields than before.

The game board consists of a puzzle of different terrain fields (mountains, hills, forests and several acreages) and is initially set up in an arbitrary distribution of these fields. Each player gets six campesinos, two wooden sticks for the dams, four fincas (small farms) and one hazienda (big farm). The buildings claim a player's possession of the acreages respectively fields and hence improve the defence of the land. At the beginning of the game the course of two rivers is determined by the players. They lay the little river pieces in turns according to the rule that the river must always flow from higher to lower ground respectively from top (mountains) to bottom (two lakes). These rules apply also for the landscape fields, where hills are higher than forest, which is higher than acreages and meadows.

There are 15 harvest cards, which also influence the course of the game in each turn. The harvest cards are shuffled and placed next to the game board as supply stack. One for each attending player plus one additional harvest cards (i.e. 3-5 cards) are placed face up in a row next to the supply stack. The outmost harvest card is the event to happen this turn, next turn the neighboured harvest event will occur and so on. When an event has been evaluated and discarded, the row is shifted by one and a card is placed face up next to the stack to close the existing gap. So the next 3 to 5 events to happen can be seen by all players.

The harvest cards contain different events:

• corn, cereal or tobacco means a normal harvest: all players obtain 100 RIO per watered and occupied acreage.
• wood cutter: all players obtain wooden dam sticks for each watered forest.
• desperados (river raiders): desperados come down the river and drive away the campesinos.

Please note that only appropriately watered fields (where rivers run through) with campesinos and/or buildings of a player count for the harvest, unoccupied fields or dry fields do not count. Harvest is the only mean of income (the currency is RIO) in the game.

A player in turn can do the following in arbitrary sequence:

• Movement: He has 6 movement points for his campesinos. One move to a neighboured field costs one movement point. When a field is occupied by a foreign campesino, the player cannot move through it except for trying to drive away. Only two campesinos of the same colour can be placed in the same field.
• Movement: Drive away an opponent's campesino: One foreign campesino can only be driven away by moving two own campesinos into the field with the foreign campesino OR by only one own campesino coming from a higher field (i.e. move from forest to a corn field). Two foreign campesinos can only be driven away, when two own campesinos come from a higher field. The affected campesinos are simply placed into the large city field and can immediately be used again in the opponent's turn.
• Building dams: A player may choose to dam up a river at a certain terrain, where his own campesino must be placed. The river pieces below that point are removed and the player in turn decides how the course of the river continues until the river reaches either reaches one of the lakes or crosses the other river.
• Raising buildings (fincas, haziendas): A player may choose to build a finca (500 RIO) or a hazienda (1000 RIO) in order to protect a certain land against offences and get closer to the victory condition. A once built finca or hazienda cannot be removed, destroyed or captured.

The game ends when either a player has been able to build the fifth building or he has built four buildings (including the hazienda) on fields which are all watered.

When a player has finished his move/turn, the current harvest card is evaluated, all players obtain the resulting resources according to the current status of the game. So each player has the possibility to yield the best benefits from the current harvest when he plans his moves at the start of his turn. After the harvest event, the current one is discarded and the next one in the rows becomes the current event for the next turn. The faced-up cards are completed from the supply stack. If this card is a desperados event, the river raiders start their activities immediately. They follow the course of the river and drive away the first three campesinos they meet on their way. Only a hazienda protects campesinos from being driven away.

Evaluation:

The gaming mechanism is simply turn-driven - not designed for big strategic efforts. Nevertheless, the possibilities a player possesses each turn to yield the best result of the upcoming harvest are fascinating enough. The player has to weigh up the chances of conquering opponents' fields against redirecting the river with dams. Where and how can he obtain the best harvest results?

The game design is quite fine and detailed, which I personally like a lot. Many different tokens are on the game board, many possibilities of settings up the game board itself. The course of the rivers will change dramatically during the game, so there are lots of possible interactions and changes. DOS RIOS will never be a boring game!

Although the game works quite well for two, the best number of players is 4. This means, there is not very much space on the game board, thus this leads to the most vivid flow of the game.

Some additional rules would add a bit more spice to the game, for instance there is no possibility to destroy or conquer an opponent's finca or hazienda. An interesting rule extension would be to allow this! Three own campesinos could conquer an opponents finca and either destroy it or claim it as an own finca. Haziendas should be strongholds as they are meant to be, they cannot be conquered. If a finca should be protected against offences, a campesino should stay there permanently.