Payoff of a dice game I came across this question today: 

"A fair die is tossed. If 2,3 or 5 occurs, the player wins that number of rupees, but if 1, 4 or 6 occurs, the player loses that number if rupees. Then find the possible payoffs for the player". 

My textbook has then proceeded to solve it like this: 

What is the logic behind directly adding all the values? Secondly, how is it that the game is unfavorable to the player? There is an equal chance that the player will get 2, 3 or 5 and 1,4 or 6! 
Please help. (Also note that this doubt is not specific to this problem alone, since this concept is crucial to understanding this part of the chapter "Probability".) Much thanks in advance :) Regards.
Edit: Thanks ever so much for these answers :) I read up on "Expected values" but encountered another important doubt. I have posted it here and hope that you will clear my doubt :) 

Perhaps instead of "Then find the possible payoffs for the player" it meant "would someone expect to make/lose money playing this game?" They are testing a concept called "Expected Value".
Let's run through an easier example, then go back to the one your book mentions. If I have a fair 50-50 coin, and I say, "Heads, you get one dollar, tails you give me two dollars", you wouldn't want to play that because you'd expect to lose money. How much money would you expect to lose? It would be $ \$1\cdot\frac{1}{2} + \$(-2)\frac{1}{2} = \$ (-0.50) $. In other words, you might expect to lose fifty cents each game.
Apply that to this situation: the calculation your book gives in the solution shows that, if you were to play that game, you would expect lose about a sixth of a rupee each round.
