Hello, I have some questions and ideas to bounce off of you guys, if I may.

Now, first off, the game I'm making is an offshoot of D&D. You roll 1d20 to attack and a bunch of funky dice to determine damage.

Physical attacks usually involve rolling two dice for damage (one die for each one-handed weapon equipped, or two dice for two-handed weapons). Weapon damage scales up as you gain levels.

Magic attacks usually involve rolling three dice for damage. These also scale up as you gain levels.

It works out so that first level characters deal about 7 or 7.5 damage on average (2d6 for physical attacks, 3d4 for magic attacks). Average damage increases by one whenever you gain a level. Main-hand weapons and two-handed weapons step up their damage dice on even numbered levels. Off-hand weapons and unarmed attacks step up their damage dice on odd numbered levels.

I'm looking for ways to step up average damage without the use of modifiers.
For example, some weapons will feature properties that let you reroll 1's; that's one way to increase the weapon's average damage by one. If you can suggest any more, I would greatly appreciate it.
I am also interested in maintaining dice variance. Guns and magic weapons, for example, give you 'exploding' damage dice (when a die rolls its highest possible value, roll it again and add both rolls to the total.) This increases dice variance without (surprisingly) increasing the average by very much (since it's such an outlier, I guess?) If you can suggest any other ways of increasing dice variance, I would greatly appreciate it.

Finally, I would like your opinion on this funky mechanic:
When you attack, roll both the (d20) attack roll and the damage dice.
If the attack is 'advantaged', you have the option to swap your damage roll and d20 roll, or add any number of damage dice to your attack roll instead of to damage.
For example, let's say you make an advantaged attack with 2d8 damage dice, and you roll a 9 for the attack and a 14 (8+6) for the damage roll; you can choose to swap the attack and damage rolls to beat an AC of 14 for 9 damage, add the 6 to the attack roll to beat an AC of 20 for 8 damage, or add the 8 to the attack roll to beat an AC of 22 for 6 damage.

What do you think? Too complicated?

I don't like the funky mechanic, though not so much on the grounds of complexity but because I expect you're likely to get an effect where the bigger your sword, the more likely you are to hit with it.

Quote from: Bloody Stupid Johnson;883722I don't like the funky mechanic, though not so much on the grounds of complexity but because I expect you're likely to get an effect where the bigger your sword, the more likely you are to hit with it.

I could resolve that issue with a 'underhanded' weapon property; step up the weapon's damage die twice on advantaged attacks. I may restrict the property to off-hand weapons only, but I'm not sure if I really need to as there are diminishing returns to putting it on larger weapons (d12 is the largest possible size for damage dice, smaller dice are more likely to explode, etc.)

Quote from: Cave Bear;883702What do you think? Too complicated?

The problem isn't the complexity. It's adding extra decisions into each attack. Unless each of your players is both well versed in the rules, experienced with the mechanic, fast at doing multiple arithmetic operations so they can compare options, and quick to make decisions you will add wait time into each combat round.

Quote from: Bren;883746The problem isn't the complexity. It's adding extra decisions into each attack. Unless each of your players is both well versed in the rules, experienced with the mechanic, fast at doing multiple arithmetic operations so they can compare options, and quick to make decisions you will add wait time into each combat round.

I should probably dial it back then.

I agree with the complaints above about the "funky" mechanic. It's creative and I sort of like it for something gamey and very abstract, like a battle in Risk, but I don't like it for a RPG combat mechanic, because it seems more about dice than about the situation. The choices are both complex and not directly related to what they represent in a way that makes sense.

You can of course get +1 average damage by adding sides to the dice used. d2->d4->d6->d8->d10->d12 each give +1 average, +2 max, of course. You can also get small-probability increases by requiring combinations to occur. Like you can have the "explosion" only happen on certain to-hit rolls per weapon. A boxing glove might only get the chance to do exploding damage if the attack roll is 20, while a gun might have the chance to explode on a 10+ on the attack roll. You could also have conditions based on the skill of the attack compared to or combined with the attack roll, so some events/effects only happen with a combination of a certain amount of skill, luck, and bonuses for circumstances. I.e. a critical success/failure system that leads to different levels of exceptional results, but only part of the time - those can add up to more or less than the equivalent to +1 average per attack, but also lead to the possibility of exceptional results, without being at a flat 5% chance, and having reasons in addition to luck determining when they happen.

Quote from: Skarg;884209I agree with the complaints above about the "funky" mechanic. It's creative and I sort of like it for something gamey and very abstract, like a battle in Risk, but I don't like it for a RPG combat mechanic, because it seems more about dice than about the situation. The choices are both complex and not directly related to what they represent in a way that makes sense.

Yeah, I can get a bit carried away and overdesign things. I'm trying to get a playtest together for my game though, so I'm hoping that will give me a good feel for what to cut and what to expand upon.

As for increasing dice averages, I know that 'roll 2 and drop the lowest' can get some good results. Maybe I can work that in.

An issue with making complex use of dice in RPGs is that the players and especially the GM may not have the statistical math skills to understand what the chances are really like for certain results or not, and that can have sneaky effects on play.

For example, when a GM doesn't really understand how likely a failure is in a certain situation, they may end up unknowingly creating risks and even deathtraps, or just results that don't make much sense. It's hard enough for some players to understand the odds in basic die rolls, but when there are odds that depend on changing some numbers or rolling doubles or whatever, they'll have even less grasp. For results of things like combat, it might be ok if the game designer mastered the probabilities, but if the same system is used with GM discretion, that can be a hidden problem. One example I look for is "what are the odds that unskilled, semi-skilled, skilled, and masterful characters will fall to their deaths when climbing short or long distances using this success mechanic" and other situations like swimming or something - then if writing rules for others to use, is it explained clearly what's appropriate, so we don't end up accidentally killing off a bunch of  characters because the GM accidentally used a die roll that wasn't what he thought it was. Though, you could also mask that with a loud paragraph somewhere about telling the GM to overrule die results that seem awful.