First, my previous experience with the SHUFE's translation books was horrible.
But I do not find PAYOFF to be problematic.
The payoff is what you will get. It is not GAIN!!!
If you still think in P&L, you miss the big picture of arbitrage pricing.
You want to HEDGE the derivative asset by some underlying asset.
To HEDGE is to REPLICATE the payoff, not the gain.
Absence of arbitrage implies for two portfolio having the same Payoff in the future should have the same price.
Let's return to the Shreve's books.
Anyway, maybe these ones are good.
But for a math book, the translation is worthless.
Man, it is math not literature.
the definitions, the demonstrations, the exercises. That is all that you need.
And at the end of day, you'll need some standard vocabulary.
Anyway, these two volumes provide a good base of the financial math. Enjoy them.