## Cinemechanix Design Journal 17: Math Is Sneaky

As I mentioned last week, we noticed a few problems with the damage system for Cinemechanix. Namely, that fights were lasting a really long time. At first I thought the main problem was that I had unintentionally doubled Hero Factor (which is sort of like level in D&D--basically the overall measure of a character's badassitude). In the original version of the rules, character's subtracted their Hero Factor from damage. So if a character with HF 6 takes 10 points of damage, he soaks 6 of it and only takes 4. Unfortunately, since players also add HF to every roll, Hero Factor is basically getting applied twice.

Here's an example: Say Angel has a HF 6 and Demon of the Week has a HF 3. If Angel rolls a 5, he adds his HF to the roll for a total of 11. In order to win the roll, DotW has to roll a 9, since he only adds 3 to his rolls. But if Angle also gets to soak 6 points of damage, the demon really needs to roll a 15 just to cause one measly point of damage. If the demon rolls 15, his total with HF is 18. When you subtract Angel's total of 11, you're left with 7 points of damage. Then Angel soaks 6, leaving 1 point. So yeah, that doesn't work.

The simple solution, of course, is to drop the HF soak, which is no problem. That helps when the fights are uneven, but when two opponents are roughly equal, the fight still takes a really long time due to another problem that Josh had noticed: when characters have higher Dice Pools, the difference between rolls tends to shrink. This hadn't occurred to me since I suck at math; I had a gut feeling that more dice would mean higher rolls, and some sample rolls and playtesting bore that out, but I didn't realize how much rolling more dice affected the results. I found a site that could do the math for me and saw exactly how much the range of likely results shrinks when you roll more dice. Because of the narrowing of this range, the difference between rolls for two characters rolling around the same number of dice--and therefore the damage--gets pretty small. If both combatants are getting a 12 or higher on most rolls an Hero Factor is the same, damage maxes out at 8 points. Since I'm used to the potential 19 point range of a single d20 and I was trying to make the system less deadly than QAGS, I gave characters way too much Stamina (hit points).

The 19 point range I was thinking in also caused me to overcompensate in another way: originally, a player added +1 to his roll for every die in his pool beyond the first. So if you had a 5 dice pool, you add 5 to your roll. The idea was to give characters who were really skilled less chance of losing to some yutz who got a lucky roll. What I didn't realize was that rolling extra dice and taking the highest did that well enough without any help. Since adding up the bonus for the leftover dice was kind of a pain anyway, I didn't mind cutting it one bit.

As I was working through the system changes, I ended up writing a combat simulator so I could test things out and make sure things were working the way I wanted to (take out the "2" at the end if you want to see the version with the +1/die bonus included). Now that I'm satisfied with the results, I'm back to the rules revision, and hope to get it finished up in the next week or so.

You can improve my dice pool by supporting me on Patreon.