I have an equation which calculates damage in a video game Final Fantasy 14. After initial damage is calculated the game does three roles to determine extra damage. The first role is any integer between -5 to 5 for standard damage variation: 95% of damage to 105%. The second role is to determine if it is a critical hit. This will have a set percentage chance depending on gear for this example lets go with a one in four, 25% chance to do critical damage. This is a yes/no to do roughly 50% more damage. Finally the game roles to see if you direct hit which is a flat additional 25% more damage and we can go with a 10% chance for this. All three of these rolls are compounded with normal damage.
How would I go about measuring the standard deviation to show expected results given enough attempts?
The calculator I designed in excel is located at the below link and you can go to the Baka 1 tab to see expected damage, absolute low, and absolute high. I simulate 500 attacks each of which would get a roll described above.
https://docs.google.com/spreadsheets/d/1ELscgnbpYvE2nie5o8hdURsb4ODE8-ky1SIEB8d9Z8M/edit?usp=sharing