These following fallacies are common Calvinistic fallacies. This list is not meant to be taken that non-Calvinists do not often fall for these fallacies, but that these fallacies are ones often encountered in debates with Calvinists.

Moralistic fallacy

What it is:

The moralistic fallacy is the informal fallacy of assuming that whichever aspect of nature which has socially unpleasant consequences cannot exist. Its typical form is “if X were true, then it would happen that Z!”, where Z is a morally, socially or politically undesirable thing. What should be moral is assumed a priori to also be naturally occurring.

Where Calvinists use it:

Everywhere and always. Open Theism is wrong because it presents a new understanding of omniscience. Open Theism is wrong because God then would not be “sovereign”. Open Theism is wrong because if the future is open the Satan might win. Open Theism is wrong because then God would sometimes be “wrong”.

This article “refuting” Open Theism relies primarily on the Moralistic Fallacy: link

The Motte and Bailey Argument

What it is:

The writers of the paper compare this to a form of medieval castle, where there would be a field of desirable and economically productive land called a bailey, and a big ugly tower in the middle called the motte. If you were a medieval lord, you would do most of your economic activity in the bailey and get rich. If an enemy approached, you would retreat to the motte and rain down arrows on the enemy until they gave up and went away. Then you would go back to the bailey, which is the place you wanted to be all along.

Source

The idea is that an arguer makes an absurd claim that is not defensible. When pressed, they retreat to a more defensible position. If they win that, the again continue claiming the original absurd claim.

Where we see it:

Any time Calvinists claim that God controls everything or that God knows everything in the future. They may retreat to attempting to prove God controlled one thing or that God knew one thing in the future.

Here is one Calvinist claiming that the case of Joseph proves God’s control of all things:

The Worst Argument in the World

What it is:

I declare the Worst Argument In The World to be this: “X is in a category whose archetypal member gives us a certain emotional reaction. Therefore, we should apply that emotional reaction to X, even though it is not a central category member.” Source

Where we see it:

When Calvinists want to call the God of Open Theism “ignorant” or “makes mistakes”. The fallacy comes because usually people that “know quite a lot” or even know “everything everywhere” would not be conventionally called “ignorant” even if they might somehow technically fit the definition. Likewise, here is Matt Slick making the Worst Argument in the World when trying to get an Open Theist to say God makes mistakes: link