The math ain't mathing for this game to be even solvable most of the time, i think. That's kinda frustrating but it's also fun.
It isn't strictly math, you can make deductions based off monster placement and behavior. Everything except the bats and the skeletons have a secret to them. From there its just about making plays that are livable that also give more information. If the total between two spaces is 14, for example, they can only either be 11 and 3, 10 and 4, 9 and 5, 8 and 6, or 7 and 7. Following the special rules of the monsters, you can reason out which is even possible to appear in those spaces, and judge if you can survive a guess or not. That's just one example, but this game is full of them, and once you figure that out, you'll be winning much more often than you lose.
It takes HP to kill things and they give you exactly as much XP back. Some levels take more XP than you have HP. That essentially neans you need to find either chests or healing packs before you run out of that. If you don't get lucky and get more than 2 healing paxks close to spawn it's just not possible to reach more than 10hp for example
You can maximize your chanxes of finding healing packs by always killing as many monsters as you can but that's still not a guarantee.
Or ta least that's what i've been trying, what your strategy? So far i've only managed one win.
Paying attention to the monsters that give you/point you to chests and such is really key. (Sorry if I’m explaining stuff you already know!)
Spoilers
Like Minotaurs (6) always have a chest in one of the three spaces behind them, the knights Romeo and Juliet (9) always give you a heart scroll, there is always an egg (0) in a space next to the dragon that gives you exp. The mine master (10) (or whatever they're called lol) is always in one of the corners and transforms all mines into exp.If you go through the comments, other people will also have more and better explanations and tips.
This stuff DEFINITELY needs to be explicitly explained. I saw the "Romeo and Juliet" stamp and figured if I saw a 9-square I should just leave it alone O_O
The monsters don't "behave" either. They either die or kill you when revealed. I didn't even know that the direction they were facing was important! I just thought they looked in different directions for variety's sake.
I would never have guessed the guy holding a magic dark ball was a "mine master" and did something special if you killed it.
Deduce where monsters are and kill as few as possible. If you need to scout, kill weaker monsters to reveal squares over stronger ones. Learn the secrets of each of the monsters. Your first objective is to explore the full board so you know where everything is, and can secure all the loose experience, especially the gnome. You want to preserve your HP as much as possible while doing that. Calculated risk and deduction. If you play perfectly, you will end up with 13 hearts left over, which doesn't sound like a lot of wiggle room, but its only the difference of using HP scrolls sooner rather than later, so if you need to use a scroll at 6 hearts instead of 9, you're only losing on 3 hearts of that extra wiggle room. And if your only objective is to kill the Dragon, you have TONS of extra space if you're still getting the hang of the game.
Long story short, do not try to kill everything. Not right away. Start by just fully mapping the board, and it will get a lot easier for you. Find the exp chests, the egg, isolate the gnome, and hunt down the rat king, slime wizard, and eventually the mine lich. Then once you've done all that, start killing things until you're out of hearts, level up or use a scroll if you can't, and repeat until you have 13 hearts to kill the dragon with. Or more if you want to aim for the full clear.