I will note that the most popular tool (for reasons that will be explained) is the spreadsheet in the
DROD RPG - Basic Optimizing thread (the spreadsheet was created by Rabscuttle and added to slightly by Nuntar, so I've linked to the most recent version of it).
When dealing with heavy DROD RPG optimization, there are two extra unstated pieces of information that are nice to keep track of. The first are the
ATK Goals. That is, the next value of ATK you need to get to in order to reduce the damage from a specific monster. If you're playing DROD RPG without making any outside calculations at all, then you're limited to finding a Power Gem, trekking halfway across a hold, and then seeing if the specific monster does any less damage. But if you *do* make the calculation (which is a relatively simple mathematical formula that you *could* just plug in the numbers from notes you keep of monster stats), then you can figure out *before* you take the Power Gem exactly how much extra ATK you need.
A particular Power Gem is, in fact, useless to you if it does not let you reach an ATK Goal required to take less damage as you make your way to your next goal. Of course, you still have to figure out when the best time to take any particular Power Gem is: obviously, if a Power Gem is free then there's pretty much no question about it. But if it's time limited or requires resources that might be better spent elsewhere... well, maybe it could be put off til later.
As a quick example of this... imagine you had 200 ATK and wanted to kill a Rattlesnake as your next goal. There's several Power Gems and Shield Gems scattered around the area, and you're wondering which would be best to go for. Well, the next ATK Goal happens to be 220. That is, you'd need 220 ATK to reduce the number of hits the Rattlesnake deals to you from 6 to 5. So if there was not enough Power Gems to reach that... well, you'd know that it's not worthwhile trying to get them before taking on the Rattlesnake. (Of course, it might be worthwhile to take them to get a higher score if there was a Score Checkpoint nearby, but that's another decision entirely.)
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The second unstated piece of information is used to help figure out when Shield Gems are worth it:
Hit Count, or rather, how many damaging hits you've taken since any particular juncture. There's no spreadsheet for this - it's something you just have to keep track of yourself. Frequently, a Shield Gem may not be worth the trouble to get to it. Whether it is or not depends on how much damage it blocks from here until whenever future goal you care to state. A Shield Gem is worth it for score if the amount of damage it blocks plus other rewards that came with it outweigh the resources you spent to get there. And it's worth it for survivability if at some future goal, you end up in a similar non-zero state with more HP than you would've if you didn't take the gem.
So, say you have to spend a Yellow Key (10 points) to collect a +1 DEF Shield Gem (3 points). The Shield Gem will finally become worthwhile from a score perspective once you have taken 280 HP less damage from enemies (or 280 hits, since it was only a +1 DEF gem). Of course, the exact calculations are more complicated than that, especially for higher DEF values, because enemies that you already completely defend against don't count, and enemies that would only require a few extra points of DEF would only count for the required DEF to reach 0. So, again, you tend to make a Hit Count as a rough general guide, since it's difficult to use it in a precise manner.
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So that's two bits of rather important information that are not provided by the game. They weren't provided by Tower of the Sorcerer either, for that manner. But one thing that most DROD RPG holds have over TotS is a lack of density... that is, whilst you make the same amount of choices, you often have to walk a lot farther to test things out. So taking notes and making calculations become more and more important: it's useful to remember where all the Power Gems you haven't collected yet are, or highlight difficult monsters and leave yourself an idea of when it might be best to return and look at it again.
These are also methods that I'm sure Mike used when playing TotS: it was very important to know what you needed to cause enemies to hit you less often, especially from an optimization perspective (which Mike was involved in).
I'll note that you'll still be using some trial and error, even with your note taking. Investigating how the balance of stat trading is expressed through the hold is not a trivial task, and the quickest way to test it is simply to play the hold. But if you go in there with some possible goals in mind, then the choices you make become more informed, and you can concoct more detailed strategies. And you may, of course, find that even they don't work from time to time -- maybe you should've saved that Yellow Key instead of collecting that Shield Gem, despite the fact that it allowed you to save more HP up til now.
And one other place that note taking helps is in recording what you've already tried. I've taken to keeping
Journals of many of my routes so that on future replays, I have rough ideas of how I went through the hold (which can sometimes lead to further optimization as I play through, though updating the journal tends to be a bit of hassle at that point). There's been requests to automate this information from the saved demos, which would be very useful, especially in testing and sharing solutions.
So all in all, there are definite cases where simple note taking and calculations help you solve a puzzle more effectively. No, I don't see this as cheating: you're not having the puzzle solved *for* you. This is about recording *extra* information and calculations from the data provided for you and then making decisions *yourself* on how best to use it. It's far less cheating than using an automatic pathfinding algorithm to discover a route through an Arrow Maze (which, for the record, DROD RPG allows you to do ^_^).
In short, it's the difference between working your way through a massive trapdoor maze through trial and error, and printing out a screenshot and drawing pretty lines using logic and deduction. They're both valid methods of solving the puzzle, and there's shades of gray between the two methods (nothing's stopping you from doing all the logic and deduction in your head without making notes), but I know I certainly have more fun finally working out that one particular choice I make is the best possible choice in the situation.