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Galithar
2019-07-02, 05:47 PM
Okay, so most systems I've seen, and all that I actually know, use a passive defense. Either a static AC to beat for a hit, or a static damage reduction. Then I've seen a few that have most actions resolved by a contest between two rollers. With someone rolling for attack and someone for parry or Dodge.

Has anyone seen a system that combined the two? My thought was to give a static defense that is lower than what you'd expect for say D&D 5e, but gets augmented by a roll.

So instead of plate being AC 18 for 5e, in this system it may be 16 + 1d4. A shield could then be +2 as per standard 5e, or increase defensive die by 1 size, making AC 16+1d6

What would be the positives and negatives of using a system like this? And has anyone ever seen something like this before?

Man_Over_Game
2019-07-02, 06:07 PM
Okay, so most systems I've seen, and all that I actually know, use a passive defense. Either a static AC to beat for a hit, or a static damage reduction. Then I've seen a few that have most actions resolved by a contest between two rollers. With someone rolling for attack and someone for parry or Dodge.

Has anyone seen a system that combined the two? My thought was to give a static defense that is lower than what you'd expect for say D&D 5e, but gets augmented by a roll.

So instead of plate being AC 18 for 5e, in this system it may be 16 + 1d4. A shield could then be +2 as per standard 5e, or increase defensive die by 1 size, making AC 16+1d6

What would be the positives and negatives of using a system like this? And has anyone ever seen something like this before?

I think the important thing to call out here is what the mechanical difference is between "-1 to enemy's hit" and "+1 to my defense". It's generally easier to track all of the calculations on one side, and since defense is generally passive (you don't choose to be hit, and most games have more action on the attacking side than defense), it's easier to tack all of the modifiers onto the attack. So, in your example, why would you want to say "increase defensive die by 1 size", when you could say "decrease offensive die against you by one size"?

Honest Tiefling
2019-07-02, 06:42 PM
Also, while many battles involve mooks, they tend to be on the enemy's side, not the players. Rolling for that number of nameless characters would probably get highly annoying, really fast.

And keep in mind that RPG players are not known for their ability to sit still or their attention span. Wrangling players is hard enough without having turns take longer as the barbarian has to look for their measly d4 that they mocked the wizard for using and possibly even threw at the bard's player.

If you wanted to play around with this, I'd try to make it not a part of the rules, but something a player could buy into. Like a blessing from a luck god or unpredictable magic or a magical item. Test it out with something that could be replaced without upsetting the player or story, and kept out of the hands of easily distracted players.

Mark Hall
2019-07-02, 07:17 PM
Hackmaster (which has a free basic version) uses active defense, which varies according to fighting style and your level of surprise, with armor providing damage reduction. Shields not only augment your active defense, they often augment your passive defense, and provide a passive defense against missile weapons.

So, for example, if you're wearing Leather Armor, it provides a -2 to your defense roll, but reduces 2 points of damage from every hit. If you choose not to use a shield, you'll usually roll d20p-4 against attacks (exception: The first attack after each of your actions). Win your defense and you take no damage.

Use a shield, and you're rolling a d20p, and the shield gives you a +6 (usually) to defense. But, if you don't beat the opponent's by 10 or more, they hit your shield, possibly breaking it, and some of that damage will bleed through to you (reduced by both the strength of the shield and your armor). If you take fire from a bow or sling or other ranged weapon, not only do they need to beat your defense, but you have a flat d20 save for cover... instead of hitting you, they hit the mobile table you strapped to your arm.

If you use two weapons and attack with both of them, your defense roll is only 1d10p... you might defend, but it will be a lot harder.

Tanarii
2019-07-02, 07:25 PM
What's the difference between this and an opposed roll, just with non-d20 dice for the roll?

Forbidden lands uses a dice pool opposed roll, I like it. For total attack skill X, roll Xd6 attack, with the first 6 doing base damage (usually 1 or 2) and each additional 6 adding +1 damage. The defender can dodge or parry (weapon or shield) Yd6, where Y is appropriate skill, with each 6 negating one attack success. Then they roll Zd6 for cover + armor, where Z is the armor rating of cover and armor combined, with 6 negating a point of damage. Damage is removed from Strength score, which typically is a value in the range 2 thru 4 for most characters, with up to 5 or 6 for Fighters, Dwarves or Orcs.

CharonsHelper
2019-07-02, 08:43 PM
I think that having D&D style attack defense but with an added defense roll slapped on just slows down gameplay with little/no benefit.

I did actually go for a hybrid sort of system in the game that I'm working on (see signature if you're interested in a space western - it's basically done) but not the way you're thinking.

In Space Dogs, armor is DR. (kept #s in single digit) For ranged attacks like guns, you roll against the target's passive defense. However, the melee phase is opposed attack rolls, so in a duel one of you is hit each round. If you roll a tie, you're both hit. (unless you have a shield)

It keeps from slowing down gameplay because there's no added "defense" roll, I just combined both sides' attack rolls to happen at the time time. Of note: it's not something that you could slap onto another system - it works because of how it's tied into the initiative system. (Side-based phases.)

Pauly
2019-07-02, 08:52 PM
Okay, so most systems I've seen, and all that I actually know, use a passive defense. Either a static AC to beat for a hit, or a static damage reduction. Then I've seen a few that have most actions resolved by a contest between two rollers. With someone rolling for attack and someone for parry or Dodge.

Has anyone seen a system that combined the two? My thought was to give a static defense that is lower than what you'd expect for say D&D 5e, but gets augmented by a roll.

So instead of plate being AC 18 for 5e, in this system it may be 16 + 1d4. A shield could then be +2 as per standard 5e, or increase defensive die by 1 size, making AC 16+1d6

What would be the positives and negatives of using a system like this? And has anyone ever seen something like this before?

Skirmish level Wargames, which put more effort into modeling this than RPGs, usually have some variation of:-
Roll to hit - modified by active defenses and the accuracy of the weapon system.
Roll for armor - based on the passive ability of the armor to negate the hit and the armor penetration of the weapon. Some systems add in a “glancing hit”, others use a success/fail system.
Roll for damage - based on how damaging the weapon system is.

Mark Hall
2019-07-02, 09:03 PM
What's the difference between this and an opposed roll, just with non-d20 dice for the roll?


It is an opposed roll, but the degree of variance available is greater.

MrSandman
2019-07-03, 01:56 AM
I think that having D&D style attack defense but with an added defense roll slapped on just slows down gameplay with little/no benefit.

I did actually go for a hybrid sort of system in the game that I'm working on (see signature if you're interested in a space western - it's basically done) but not the way you're thinking.

In Space Dogs, armor is DR. (kept #s in single digit) For ranged attacks like guns, you roll against the target's passive defense. However, the melee phase is opposed attack rolls, so in a duel one of you is hit each round. If you roll a tie, you're both hit. (unless you have a shield)

It keeps from slowing down gameplay because there's no added "defense" roll, I just combined both sides' attack rolls to happen at the time time. Of note: it's not something that you could slap onto another system - it works because of how it's tied into the initiative system. (Side-based phases.)

At least one of the combat resolution systems for Fudge does basically the same thing. I think it's an elegant solution that quickens combat. It also seems more realistic to me than the usual "roll attack against defence".

Khedrac
2019-07-03, 02:43 AM
In many respects I would say that RuneQuest (Basic Roleplaying, Call of Cthulhu, etc.) uses a combination system.
The active part is the attacker rolling to hit and the defender rolling to parry or dodge (or just wincing and taking it).
The passive part is the way armor absorbs damage - a sword does 1-8+1 (plus damage bonus) but plate armor will absorb the first 8 points of a blow.

Satinavian
2019-07-03, 04:05 AM
TDE does : Attacker rolls attack (difficulty independend from defender), defender rolls parry/dodge (difficulty dependend on kind of attack), if still a hit occurs, armor works as damage reduction.

Splittermond has : Attacker rolls against defense value of defender, but defender can make a roll to increase the defense. This will cost him some kind of partial action he could use otherwise, it is an optional thing. If a hit still occurs, armor works as damage reduction.

MoiMagnus
2019-07-03, 06:24 AM
Okay, so most systems I've seen, and all that I actually know, use a passive defense. Either a static AC to beat for a hit, or a static damage reduction. Then I've seen a few that have most actions resolved by a contest between two rollers. With someone rolling for attack and someone for parry or Dodge.

Has anyone seen a system that combined the two? My thought was to give a static defense that is lower than what you'd expect for say D&D 5e, but gets augmented by a roll.

So instead of plate being AC 18 for 5e, in this system it may be 16 + 1d4. A shield could then be +2 as per standard 5e, or increase defensive die by 1 size, making AC 16+1d6

What would be the positives and negatives of using a system like this? And has anyone ever seen something like this before?

You forgot D&D saving throw. You could without problem define an armor saving throw as AC-14 (for 5e) and defines the DC of the AC saving throw as 8+AttackBonus (for 5e).

There is still one roll per attack, but it is now passive attack against active defense instead of the contrary.

You could try a double roll, one for attack and one for defense, however it significantly reduces standard deviation. The statistical phenomenon is quite similar to what happen when you're using 2d10 instead of a d20 for attack rolls. (The more you roll dices for a check, the less it is random).

As a consequence of double rolls, easy fight are made easier, and difficult fight are more difficult. (If it is a bad or a good thing is up to you).
Oh, and double roll also slightly slow down fight, but you probably guessed that point.

How to change 5e into a double d20 roll system:
AC is replaced by Armor saving throw, with bonus AC-14.
Attack bonus remains the same.
Saving throws remain the same.
Difficulty challenge for saving throws become an attack roll, with bonus DC-8.

How to change 5e into a double d10 roll system:
AC is replaced by Armor (d10) saving throw, with bonus AC-9.
Attack bonus is increased by 5 (and now use d10).
Saving throws bonuses are increased by 5 (and now use d10).
Difficulty challenge for saving throws become a (d10) attack roll, with bonus DC-3.

Spore
2019-07-03, 08:05 AM
Both people rolling only really makes sense with dice pool systems like in WoD's storytelling systems. Because then you have a normalized distribution on both sides. Advantages are, that a skilled super swordsman can still be injured/killed by a lucky hit, and you avoid abominations like a swordsman with terrible armor class.

Imagine a sword wielding 5e Fighter. Str 16 Dex 14 and a Leather Armor. This means AC of 14, which is terrible. In dice pool systems both factions could roll rivaling melee rolls and if the attacker wins, you still have armor (maybe the armor is a success threshold, or it is flat damage reduction).

Psyren
2019-07-03, 11:33 AM
Pathfinder 2 has a fiddly "raise your shield" action that adds to your defense. Not an opposed roll but it is a combination of active and passive defense.

Something closer to what you're looking for is like the riposte/parry mechanic that the PF Swashbuckler and Duelist get.

Galithar
2019-07-03, 04:06 PM
I think the important thing to call out here is what the mechanical difference is between "-1 to enemy's hit" and "+1 to my defense". It's generally easier to track all of the calculations on one side, and since defense is generally passive (you don't choose to be hit, and most games have more action on the attacking side than defense), it's easier to tack all of the modifiers onto the attack. So, in your example, why would you want to say "increase defensive die by 1 size", when you could say "decrease offensive die against you by one size"?

Because offensive rolls will be either a d20 or 3d6. Reducing the die size there doesn't make sense, but if giving the defender an active roll to modify their defense adjusting a d6 up or down is fitting.


Also, while many battles involve mooks, they tend to be on the enemy's side, not the players. Rolling for that number of nameless characters would probably get highly annoying, really fast.

And keep in mind that RPG players are not known for their ability to sit still or their attention span. Wrangling players is hard enough without having turns take longer as the barbarian has to look for their measly d4 that they mocked the wizard for using and possibly even threw at the bard's player.

If you wanted to play around with this, I'd try to make it not a part of the rules, but something a player could buy into. Like a blessing from a luck god or unpredictable magic or a magical item. Test it out with something that could be replaced without upsetting the player or story, and kept out of the hands of easily distracted players.

I would agree if I was trying to drop this into an existing system. I feel that writing it into the base rules from the beginning would work. Especially since my design intent is to be most effective when a party of 3 or 4 encounter enemies who number between 2 and 6. I don't know about you, but as a DM a quick d4-8 roll behind the screen (or in the open if you prefer, I use a screen but that's besides the point here) is not going to slow me down much. The concern wouldn't be rolling for the nameless, it would actually be more cumbersome waiting for your players to make their defensive rolls each attack but I don't think I'll plan around slow inattentive players as no matter the number of rolls they would slow the game down. But it is something I'll keep in mind to prevent the rolls per turn from getting out of hand.



What's the difference between this and an opposed roll, just with non-d20 dice for the roll?

Forbidden lands uses a dice pool opposed roll, I like it. For total attack skill X, roll Xd6 attack, with the first 6 doing base damage (usually 1 or 2) and each additional 6 adding +1 damage. The defender can dodge or parry (weapon or shield) Yd6, where Y is appropriate skill, with each 6 negating one attack success. Then they roll Zd6 for cover + armor, where Z is the armor rating of cover and armor combined, with 6 negating a point of damage. Damage is removed from Strength score, which typically is a value in the range 2 thru 4 for most characters, with up to 5 or 6 for Fighters, Dwarves or Orcs.

The difference is significant. In a d20 opposed roll system you stand to have a very good roll negated by a opposed good roll. (This also applies to a dice pool system) Or a very bad roll hit because of an opposed bad roll. (This part not so much with a dice pool, but I'm not designing a dice pool system) With a hybrid, smaller defense die added to a static defense, you get smaller defensive fluctuations. It allows for that really good roll to hit (18+7, 25 to hit still hits a 17+1d6 even when they roll a 6) and the really bad roll never will hit.

In addition it adds more options to modify armor. I could have heavy armor that is 19 with no modifier, or 15 + d6. This is now a decision you can make as a player. Do I go with the marginal statistical advantage of a 19? Or go with the possibility of a 21 sometimes, but a 16 others?

This would allow me to add more distinction between armors. Now it's not just 'Plate' a modifier like 'Mithral' could have a much larger mechanical difference instead of D&Ds "it's lighter". It could open up the possibility of layering armor. Maybe I take a "realistic" approach. Your plate gives you a 18, but now it's literally just the pl of metal. Are you putting a Gambeson on underneath? Now THAT decides your defensive die (modified by skills as appropriate)

Those are just some of my ideas for making distinctions that require a system like this (at least to work how I'm imagining it).

Also, I don't know about you, but my players LIKE to roll dice. Giving them a consistent roll on someone else's turn, even if it slightly slows the game, will keep them engaged with the action more. Which is an issue when tables get to have 7 players (like mine currently does). They act fast(ish) on their turns but lose interest during every other turn. This gives them a reason they have to pay attention, at least to the enemies turns.

Man_Over_Game
2019-07-03, 04:37 PM
Because offensive rolls will be either a d20 or 3d6. Reducing the die size there doesn't make sense, but if giving the defender an active roll to modify their defense adjusting a d6 up or down is fitting.

In that specific circumstance, maybe, but the same thing could be applied with a bonus or a penalty. Increasing a die size is the same average value of a +1 (1d6 to 1d8 is 3.5 to 4.5, or a +1 gain).

Unless there is a specific reason to include multiple dice for an attack rather than a single die with modifiers, or unless there's a reason to avoid adding modifiers altogether, I'd recommend a different approach.

Or rather:


Try to put most of the changes on one size, unless you have a reason not to.
Try to keep most of the dice to be the same type/number/size, unless you have a reason not to.
Try to use modifiers to keep things streamlined, unless you have a reason not to.



For example, choosing your offensive rolls to be 1d20 or 3d6 isn't enough of a justification to not being able to apply a -1 penalty to hit. However, if you were a specialized defensive build that managed to get your defense up to 1d12, and you still can bump it up once more (to the point where there are no more dice sizes to increment it by), and there's a special bonus for doing so, THAT'D be a valid reason.

If doing something would make the game simpler, either find a reason to make it fit, or find a reason that your method is better. Or, if there isn't a reason, make one. Because, right now, I'm seeing some cool concepts that can be built upon, but don't' have any major justification why they couldn't be streamlined using modifiers.

Galithar
2019-07-03, 04:59 PM
In that specific circumstance, maybe, but the same thing could be applied with a bonus or a penalty. Increasing a die size is the same average value of a +1 (1d6 to 1d8 is 3.5 to 4.5, or a +1 gain).

Unless there is a specific reason to include multiple dice for an attack rather than a single die with modifiers, or unless there's a reason to avoid adding modifiers altogether, I'd recommend a different approach.

Or rather:


Try to put most of the changes on one size, unless you have a reason not to.
Try to keep most of the dice to be the same type/number/size, unless you have a reason not to.
Try to use modifiers to keep things streamlined, unless you have a reason not to.



For example, choosing your offensive rolls to be 1d20 or 3d6 isn't enough of a justification to not being able to apply a -1 penalty to hit. However, if you were a specialized defensive build that managed to get your defense up to 1d12, and you still can bump it up once more (to the point where there are no more dice sizes to increment it by), and there's a special bonus for doing so, THAT'D be a valid reason.

If doing something would make the game simpler, either find a reason to make it fit, or find a reason that your method is better. Or, if there isn't a reason, make one. Because, right now, I'm seeing some cool concepts that can be built upon, but don't' have any major justification why they couldn't be streamlined using modifiers.

The simplest reason I edited into my last post as I responded to Tanarii. My players like to roll dice. Giving them another die to roll is always good. Modifiers are great, but so is rolling dice.

What's the statistical hit chance of 1d20+5 vs AC 17? You hit on a 12+ for a 45% hit chance.
What's the statistical hit chance of 1d20+5 to hit AC 15+1d6? I honestly couldn't say, without doing good bit of math. But it's not math you have to do every attack. You just roll a single die and add two numbers. It's not like this is a significant complication. I am aware that more rolls slows the game, but when it's a roll for 'how does my character do?' I find most (of my) players enjoy reveling in the victory of a good roll or cursing the dice gods for bad ones.

Now this system of course allows for a great defensive roll to still get hit, but I haven't designed this to put all the power of chance in the hands of the player.

KineticDiplomat
2019-07-03, 06:16 PM
So, the most accurate melee systems I know - that remain playable, at any rate - treat defending yourself as an action, but taking the hit as a static calculation. After all, even the least trained peasant holding a sword the wrong way can chop a static post.

Usually it becomes a game of committing limited resources between attacking and defending, and to a certain degree knowing how to manage your maneveurs/movesets. Then if you actually get the hit in, that’s when you worry about armor and whether or not you can actually do much with that fist.

Duff
2019-07-03, 11:46 PM
If it's purely a matter of wanting a greater range of results, simply have the attacker roll more dice.

d20 vs d20 and 2d20 vs 21 are the same (if I've remembered the math right).


OTOH, if an "Active Defence" is the defender doing a thing (parry, dodge, etc) then the player rolling for how successful their thing is gives the player a sense of agency even if the math is the same.

ErdrickOfAliaha
2019-07-04, 08:03 AM
Quick reminder: in D&D, AC 10+x is an example if the defender "taking 10" on their defense roll. As I recall, it was a rule variant in a DMG (2e? 3e? 3.5e? Idk).

On a side note, opposed rolls for attack/defense work better outside of d20/d100, ime.

Mark Hall
2019-07-04, 09:33 AM
Quick reminder: in D&D, AC 10+x is an example if the defender "taking 10" on their defense roll. As I recall, it was a rule variant in a DMG (2e? 3e? 3.5e? Idk).

On a side note, opposed rolls for attack/defense work better outside of d20/d100, ime.

I know it was an option in 3.0

Tanarii
2019-07-04, 11:58 AM
What's the statistical hit chance of 1d20+5 vs AC 17? You hit on a 12+ for a 45% hit chance.
What's the statistical hit chance of 1d20+5 to hit AC 15+1d6? I honestly couldn't say, without doing good bit of math.
Assuming the attacker needs to get equal to or greater than the defense roll (ie Hit the AC), 37.5%. Using anydice.