Imagine 2 envelopes, A and B. Inside both envelopes is a hidden binary code, just printed on a card.
These envelopes are sent to Alice and Bob. However, Alice doesn't read the code directly. She first generates her own pseudo random stream of random 0's and '1's. She can control the ratio of 1's and 0's, by initially choosing an angle, and the Generator will spew out a sequence that all '0's if the angle is 0degrees, or all '1's if the angle is 90degrees, and any angle between 0 and 90 will adjust the ratio accordingly.
Alice then X'ORs her stream of 0's and 1's with that printed on her card, in the envelope, to give a result.
At the other envelope, BOB does exactly the same. He also has a pseudo random number generator, (using the same seed as Alice). When he sets his angle to 0, and Alice sets her's to 0, they will BOTH end up with the same sequence on the PRNG, and so XORing the number on the card will result in the same message. In fact when Alice and Bob set their PRNG to the same angle, they always will get the same sequence, and so their message will always match. Nothing spooky going on here.
The spooky thing happens when Alice and Bob choose different angles. Lets say that Alice sets her angle to 0 degrees, and Bob chooses 30 degrees. They do the calculation, and it appears the final sequences correlate 3 out of 4 times.... or 25% of the time there is a difference between Bobs and Alices code. Bob then changes his angle back to 0, and Alice sets hers to -30 Degrees. Again, after doing the calculation, they work out that 25% of the time the codes differ.
If alice sets hers to -30 and Bob sets his to 30, it would be common sense to say that there could be no more than 50%, the codes will differ. Except this is not the case. In the real world, using real entangled particles the result comes out to be 75%. What *must* be happening for this result, is the original hidden code printed on Alices and Bob's card MUST some how change, when the other party changes their angle.... OR, that there is no hidden code, but something else is going on... No hidden fixed sequence of numbers can explain the experimental results. This is 'Spooky' action at a distance, and can't be explained using traditional physics on its own.