Been working on creating some better combat mechanics and options for Auto Fire lately. One of the factors I was working on was tangibly having hit chance be affected by tactical choices such as “painting” a target with radar for more accuracy, or on the other side moving faster to avoid getting hit. I got those systems in but it didn’t really seem to matter.

I had to seriously think of how I’m dealing with accuracy, range and speed. My initial version of the combat system in Auto Fire was inspired by the system in Diablo II. It used this sort of calculation:

Chance =200% * AttackRating /

(AttackRating + DefenseRating)

Consider AttackRating to include things like gunnery skill, weapon accuracy, and other targeting bonuses. DefenseRating in contrast is stuff like range, target speed, and target size.

Multiplying the value by 200% gives the player 100% hit chance whenever the Attack Rating is more than 50% the Defense Rating… So in the average case the player is guaranteed a hit. This was the system I used in X-Men Legends, and it feels pretty good in an action game where you are directly controlling your character and only want to have misses when your opponent clearly outclasses you.

The problem with this method is that the chance to hit tapers off because it never reaches zero… Thus, I was finding that there’s only a small sweet spot where hit bonuses mattered between 100% chance and maybe 60% chance.

If you like numbers, here are the results of that sort of calculation.

I made some changes and pushed the system more towards a classic “opposed totals” method more akin to D&D or most pen and paper games.

Chance = (base + AttackRating – DefenseRating) * 10%

It’s not original, but what it did was make each bonus you earn through improved targeting, or sustained fire (or penalty from moving fast) has a pretty chunky impact on the hit result.

Here’s that table if you’re feeling nerdy.

I do put a minimum hit chance of 10% just so it’s not worthless to attack, and I’m not sure what increasing the miss chance is going to do to the feel of the game.

I have a mechanic where excess above 100% is used as a critical chance (That is, 130% chance is an automatic hit with a 30% crit chance). I might consider doing the same on the bttom so a “miss” is a glancing blow that still does a little damage, progressing to a real miss based on the percentage. (For example, -30% is a 30% chance of a real miss and a 70% chance of a glancing blow).

I’m wrapping that back into weaponry definitions and looping back around to where I can try the new system in the wild. From there we’ll see what happens.