"A Firepower vs Armor question. " Topic

I am thinking about the feasibility of designing my own game. (Shocker)

But I think I hit a brick wall.

I would like to incorporate a Firepower vs. Armor mechanic into my game but would like to make the it as an Opposed-Roll.

For example my tank fires a shell that has a fire power rating of 5 and it hits another tank with an armor of 6.

Normally in most games the shell would bounce off the armor in the above example. But I want to include a chance where the shell might penetrate, and the defending tank would need to make a roll to defend itself.

I would also like there to be a chance where a tank with fire power of 6 hits a tank with an armor of 5 would still have a chance to survive.

Not sure how to make this work or if it's workable at all.

Any ideas would be appreciated. THX

Some things to think about:

What does the firepower vs armor roll represent? Is it the chance of the weapon doing damage to the vehicle? Is it the chance of the weapon penetrating the armor, then another roll for damage applied? Does the roll involve accuracy or ability to aim at the target? What kind of statistical results would you expect? (1 die will give results all over the spectrum, 2 or more die will give some kind of bell curve. The more dice, the more chances of an average total).

Possible mechanic: The values determine how many dice to roll, highest roller wins. ie. FP5, Arm6 so attacker rolls 5d6 firepower and defender rolls 6d6 armor.

Another mechanic: FP – Arm + die roll vs a target number.
Same guys: 5 -6 + 2d6 , must roll 9+ to damage or 11+ to kill (tweak to taste, of course)

Another mechanic: Roll dice, look for specific numbers (attacker's 1's hit, but defender's 1's negate those hits)

Having one player roll, evaluate dice, then the other player roll, slows the game down a lot. Better to have both players roll at the same time then evaluate. Even if the defender doesn't need to roll, having the dice done will speed up play.

Doug, download the rules for the boardgame World at War: Blood & Bridges plus scans of the game's counters from BBG. It does everything you are asking about.

Fireball Forward uses an opposed role for penetration. Check it out.

Thanks for the suggustions!

2 dice produces an easy results chart. Propose a formula, lay out the distribution, consider the probabilities, assign results accordingly.

For example suppose your formula is:

FP + Acc – (AR + Ev) = ODC

where
FP= Firepower, Acc= Accuracy D6,
AR= Armor, Ev = Evasion D6,
ODC = Opposed Dice Check

A 2D6 chart is easy to lay out, FP+Acc on the vertical axis, AR+Ev on the horizontal. Plot the results on the grid. I won't render that here.

For FirePower 5, Armor 6, the ODC range is (fractions rounded):

4 = 1/36 ~= 3%
3 = 2/36 ~= 6%
2 = 3/36 ~= 8%
1 = 4/36 ~= 11%
0 = 5/36 ~= 14%
rest = 21/36 ~= 58%

Your desired results range when hitting is:

. . . Normally . . . bounce off . .. But . . . might penetrate

So if "might" is 3% (once every 36 times), then require a 4 result to penetrate. If "might" is more often, a 3+ happens about 8% (once every 12 times), a 2+ about 17% (every 6th time).

If 58% of shots missing is a reasonable number, then that's your negative result.

The range in between (0 to 2, 0 to 3, 0 to 4 depending) represents "bounce off". A hit that didn't penetrate.

The flaw with this system is that higher firepower shots are inherently more accurate and harder to evade.

So what you may prefer to do is throw an accuracy die versus an evasion die (Acc – Ev = ODC) : Negative result = miss. Positive result= hit. High positive result, specially accurate hit (if you want to model that).

Then compare FP versus AR to determine effect. Typically you'll want a range of results here (i.e., a chart) which can be determined either by rolling a 3rd die, or just carry over the positive hit ODC result (so higher accuracy => more damage).