I would like these alphabetised

I believe even almost all of expert mode's difficulty comes from a few math variables. Not counting exceptions that were manually changed, any values are determined and changed by an initial value. Monsters deal double damage. Simple enough to grab the mob's damage (Say B) and multiply it. If (WorldDifficulty = 2); B = X * 2; Or player defense reduction (Final damage = F, Defense = D) If (WorldDifficulty = 2); F = B - (D * 0.75);

You can speculate all you want. Your opinions are literally nothing but guesses.

The devs use minimalist solutions wherever possible to avoid lag. This is common practise in games programming. The devs use a separate damage value for expert mode. They don't waste time calculating when they don't have to, because as I said before, every little bit of lag stacks up in the big picture.

an oversight, or the most likely, they just didn't think about it.

You mean they live in a cage and haven't noticed the first thousand of these discussions that have been posted over the Terraria community? Or it was a design choice to order them by item ID. You're talking nonsense.

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