In Riven two core puzzles need to be solved to complete the game. Each puzzle requires a significant amount of time spent in detailed study of various clues provided in the game. A number of minor puzzles must be solved to access these clues. These two, core puzzles are the tombstone puzzle and the fire-marble puzzle. The tombstone puzzle is arguably more difficult to solve as it involves deciphering a specific clue, which is not at all obvious, and is spread over two islands in different locations.
A sequence of tombstones must be pushed in order to gain access to the Tay linking book. The cork balls found at various locations around Jungle Island provide clues as to which tombstones have to be pushed, and in what order they have to be pushed.
Each cork ball (except for one) makes a distinct sound - the sound of one of the animals of Riven. One of the animals (the fish), by its very nature, does not make a sound. Each ball also has a D'ni numeral inscribed on its reverse side. The table below gives the solution:
Given the correct sequence consists of 5 tombstones, out of 25 tombstones, that must be pressed in the correct order, the total number of possible combinations is 6,375,600.
Fire Marble Puzzle
Five fire marbles must be placed correctly on a 25 by 25 grid. Find the color associated with each dome from the rotating shield cover. (Look for the yellow colored symbol.) Find the grid location for each dome from the topographical extrusion device found on Plateau Island. Note that the grid is subdivided, by a bold line, into five regions, each region corresponding to one of the five islands of Riven.
Each region in turn is subdivided into squares, each square representing a 5 by 5 portion of the of the 25 x 25 grid. For each island, a colored fire marble must be placed in the indicated row and column of the starred (*) square, shown in the table below. The location of the fire marble in the starred 5x5 square is identified by the notation: (row, column) after the corresponding marble color.
In this puzzle we have to select 5 out of 6 unique marbles and place them in the correct locations on a 25 x 25 grid. To a close approximation this results in 5.631x1014 possible combinations.
Red (2, 4)
Orange (2, 1)
Purple (4, 2)
Green (1, 1)
Blue (1, 2)
- To access the tombstone puzzle:
- Go to Gehn's wahrk gallows throne and close the gallows floor. Access the throne by taking the Jungle Island elevator (wooden wahrk sculpture in jungle) to the 3rd level. Look for the little push button near the sculpture.
- Via the boardwalk to the village, go up the ladders to the oven for smoking fish, find the control lever, and pull the lever to lower the submarine.
- To board the submarine, go all the way around the island, past the seal creatures, through the village back entrance, and down the ladders.
- Take the submarine to the control tower and extend all station ramps.
- Take the submarine to the school house to learn how D'ni numerals are written. (This is a major clue: you will need to be able to decipher D'ni numerals to solve other, key puzzles in the game.)
- Take the submarine to the wahrk gallows and ride the trapeze to top of the gallows.
- Open the prison cell and find the secret entrance latch in the drain.
- In the dark, go to the end of the tunnel and activate, one by one, the fire marble lights.
- Find the secret door to the tombstones.
- To access Gehn's office:
- Go out to the valve in the center of the lake and switch power to the wood pulp cooker.
- Go to the wood pulp cooker. Turn off the heat, raise the grate, and empty the boiler.
- Go back to the valve in the center of the lake and return the switch to its original (3 o'clock) position.
- Go inside the boiler and down the drain, through the pipe, and out the end of the pipe.
- Follow the path to the platform and open the hatch.
- Open the double doors. The path straight ahead leads to a ytram trap. Trap a ytram to hear the sound that a ytram makes.
- On the way back from the ytram trap, close (from the inside) the double doors to reveal two hidden passages - one to the linking book dome and the other to Gehn's office. Take the passage to the right.
- Turn off the fan (switch next to the walkway on the way to Gehn's office). Go back to the ytram trap and climb up past the fan into the tunnel. Follow the tunnel to Gehn's office.
- Once in Gehn's office, unlock both doors from the inside.
- To access the lower level via the tram to Crater Island: board the tram and turn the car around, but do push the lever that starts the tram moving. The car door will open, allowing access to the lower level. The lower level can also be accessed by the tram from Jungle Island.
- Take the elevator to the top level to find the topographical extrusion device. Use this device to find the grid location of each of the 5 linking book domes. To set the device to an island, go back past the elevator and find the island selector. (Look down.)
- To determine the color symbol associated with the Plateau Island linking book dome, go to the dome and look for the yellow colored symbol. (Do not open the dome.)
- In the lower level, follow the walkway to Gehn's underwater observatory. Ascend the stairs and sit in the throne to discover how to interpret the D'ni color symbols. In the process, discover the sound that a wahrk makes.
Prison island is where Catherine is imprisoned. The island can only be reached via a linking book in Gehn's office in his 233rd Age.
- To find the combination to the elevator cage, go to Gehn's (basement) bedroom in his 233rd Age office. Look for the spherical shaped device on Gehn's bedside table. Also find Gehn's diary there.
The five sided room may be rotated to provide access to different areas of
- To access the power dome:
- Rotate the five sided room four times. Go to the right, down the stairs to find a wooden gate.
- Go under the gate to access the five sided room. Go through the five sided room to a tunnel; there slide the gate lever up and turn on the telescope steam valve.
- From this location, rotate the room twice to access the other gate lever. Go through the five sided room. Slide the gate lever up to open up the route to the power dome.
- Rotate the room twice to access the main entrance. Go through the five sided room to the main entrance.
- From the main entrance, rotate the room twice. Go through the five sided room and through the power dome to access the steam valves that power the drawbridge and power the access ramp to the fire-marble power generator. Turn on both steam valves.
Addendum - A Note on D'ni Numerals
D'ni numbers are expressed in a positional, base twenty five number system. Each D'ni numeral may be constructed from one or two symbols taken from a set of five primitive symbols. In the chart below, the five primitive symbols are shown in the left most column.
Rotating a primitive symbol 90 degrees (counter-clockwise) multiples the value of the symbol by five. In the chart below, these rotated symbols are shown in the top most row. Superposing a primitive symbol on a rotated symbol adds the value of the superposed symbol to that of the rotated symbol.
A D'ni number may be expressed algebraically in base ten as
N = dn25n + ... + d0250
di is the decimal value of a D'ni numeral.
expressed in base ten notation is
9(251) + 16(250) = 9(25) + 16(1) = 241
Chart showing all 25 D'ni numerals