EV is Exposure Value. It is the amount of light available in a scene. In the old days, a photo meter is used to find this value. In todays modern camera, it is shown in the viewfinder. The value depends on the area being measured by the metering mode. In a Nikon it is a divided linear graph with a plus & minus sign on each end.
+ -----|----- -

If your camera exposure setting is incorrect, the bar highlights the side that it is over or under exposed, the length shows how much "off" to the side of the wrong setting the exposure is. In this sample, the metering says the setting is several stops under exposed.
+ -----|----- -

In the real world, adjustments to correct exposure setting to this EV value can be modified so that each click (or step) can be 1 full stop, 1/2 stop or 1/3 stop of change. That is because a stop is a big value. A full stop is is either to double the total amount of light allowed into the sensor or cut the light in half.

In the game, the EV value is fixed to equal to 1 f-stop of change for every card.

In the median board(Cloudy lighting scenario), proper exposure needs 10 cards. Less than that and the image will be darker (EV -number) and if more than that, the image will be lighter(EV +number). So the player has 10 slots to mix and match the 3 main cards depending on what is the priority.
In the bright light scenario-Sunlight, the proper exposure use only 8 cards. The Playing board is marked with EV-2 because with reference to the median setting, it is 2EV brighter. If we add this -2 to the total EV in 8 cards, it would be 0 or proper exposure. This is assuming that you were set to median light, then suddenly the sun came out. You are now over exposed with your present setting. Hence if (you adjust the camera settings) take away 2EV, then you will be ok for the bright scene. The opposite is applies to the Shade playing board.
The correct exposure for the board being used should be zero. With reference to 10, any number after ten will be -EV for every tile and numbers below 10 will add +EV each.


As for playing with a dice, that is a very good idea.
With a dice, it can be also played with 2 or more players.
Decide who goes first or each player throws a dice and the highest number starts the game. If the highest digit is thrown is by 2 or more players, each who get the highest digit shall throw again.
If there is more than 2 players, second player would be to the left of the starting player and so on.

Have 10 flash cards & 10 ND Modifier cards, mix and lay face down as draw cards for doubles thrown by the dice during gameplay.

I recommend using 3 six sided dice as its minimum number would be 3. The minimum card required.
The number throwed would be the size of the playing board. Still with reference to 10, any number after ten will add -EV and numbers below 10 a +EV.
3 would be a very bright scenario, something like an atomic blast and would definitely mean a zero points turn because there would not be any choice to it.

After throwing the 3 dice to have the size of the board, a single dice will be thrown. This will now set the need of the scene.
With a correct exposure:
1=Freeze me (get the lowest motion blur)
2=Butter light (get the highest motion blur)
3=Bright eyes (seek the lowest ISO)
4=Best bokeh (highest BG Blur is king)
5=The Landscape(aim for the smallest aperture)
6= Choose for the player (Be imaginative - give a good challenge)

Then the last 2 dice is thrown again.

The player can then decide which of the numbers up on the 2 dice will be his target and prize point.

Example, a player on his first throw gets 2, 3 & 4.
So the playing board for that round would be 9EV long. Since its less than 10blocks, a -1 EV will be counted with it. That is a slightly brighter scenery

At the 4rth dice we get a 4, so his aim would be to get the highest Background Blur possible in the 9EV board.

5th & 6th dice we get a 3 & 4.
He can choose to aim to surpass the lower number(3) and get 4 points.
or
He can aim to surpass the higher number(4)and get more points for every number more than 4.
Example: If the player was able to get BG Blur +6, then he/she gets 4+2 points.
or
He can add both numbers and if able to equal or surpass it, player gets 12 points!

Player also gets a chance to draw a modifier card because the last 3 dice throw has a double number. 4-3-4

If it was a triple like 1-1-1, 2-2-2, 3-3-3, 4-4-4, 5-5-5 & 6-6-6, he draws 3 modifier cards.
Modifier cards can be used in any of his turns. But at the end of the game, each modifier not used is equal to minus 10 points.

The next player only throws 3 dice and follows the rule or dice 4,5 & 6.
After all players have played the board, then a new board will be played. This time, the second player will throw the board size, even though it will still be played first by the starting player. The next player will throw the third board and so on, after all players have played the board thrown.

Game can be played in a best of 5 or best of 10, or first to get 50points etc.