I might have read the information wrong, and I could be wrong, if I am wrong please don't mock me!

You have no idea how hard it is to read 2-3 pages of calculus and calculus explanations, and then to simplify it. This here comes from hours of reading, and doing my own calculations, and being like "wait whaaa?" and rereading. I had to keep pulling at my hair and slapping myself on the head for this, so I hope this post is worthwhile! And I also hope it's not wrong haha!

Warning the calculations are easy, if you're willing to work through each step. But it might seem hard, cos your mind might be like "can't be bothered, too hard" merely because of the lengthiness of it, not because it's actually difficult.

The formatting is a little weird, but it's fine I guess

**Step 1a**You need to calculate your natural armour base. This is your natural armour base without wearing any armour whatsoever!

**Step 1b **Calculating your natural armour base if you have 99 defence. Remember to imput your own defence level into the formula. In this formula I've used 99.

0.0008 x 99^3 + (4 x 99) + 40 = 1212 as you need to round down.

**Step 1c**Calculating your wearing armour base: All you need is the level required to wear the armour. So lets say you need level 99 to wear the armour you input 99 into the exact same formula in step 1b. Now if you're wearing rune, you input 50 instead. But I'm too lazy, so I chose 99, cos I already know that inputting 99 gives me 1212

**Step 2a**Calculating for each individual piece of armour: Base in this formula means your base from step 1c, NOT your base from step 1b! So in other words your armour armour base, not your natural base.

A full helm = 0.5 x base = 0.5 x 1212 = 606

A shield is also 0.5 = 606 - shortened it, cos it's obvious

Platebody = .575 x 1212 (remember 1212 is the base) = 697

Leg/Skirt = .55 x 1212 = 666.6) but round up to 667

boots = .125 x 1212 = 151.5 or 151

gloves = 151 cos it's the same as boots with a .125 multiplier

Now add it all up: 606+606+697+667+151+151 = 2878

Now remember the number you got in step 1b? It was 1212.

2878 + 1212 = 4090

4090 is your total armour base with 99 defence, and wearing full armour with shield that requires 99 defence to wear.

**Step 2 b**Finally the part you actually care about! You need to know the accuracy of the monster you are fighting, if you go to the deadly red spiders wiki page, which is the monster I will be using for this calculation example, you will see in their stats that their accuracy is 1409.

**Step 2c**So the chances of the monster hitting you is: Multiplier x (the monsters accuracy/ by your total armour base)

So the multiplier is always 45, 55, and 65. To know your multiplier you only need to know the combat triangle.

DRS use range attacks.

If you are wearing mage armour which is weak to range attacks, you will have a 65 multiplier

If you are wearing melee armour which is strong to range attacks you will have a 45 multiplier

If you are wearing range armour which is neutral to range attacks you will have a 55 multiplier

Since DRS are weak to melee, I am going to assume that the person in this calculation is wearing melee armour. So we will use 45 as our multiplier

45 x (1409/4090) = 15% chance of DRS hitting you.

Or if that's confusing its 45 x (the accuracy of the drs given to you on the wiki page/the final number you got in step 2a)

Phew!