O.R.C. Opposed Roll Combat for Dungeons and Dragons 3.5 and 5E

I’ve been putting this off for some time due to having lost my first draft.  I hate re-doing work, but I finally got around to re-writing this last night.  This is my concept of an alternative to the Armor Class (A.C.) system used in Dungeons and Dragons 3. 5 and 5th Edition (this alternative works as is in both editions).

It’s quite a bit more complex, and requires more bookkeeping.  I know that this is not a fact that most gamers like; many RPG’s are already too complex.  However, I simply don’t like the A.C. system, never have, and feel it’s time for an alternative.  I’ve got it all figured out as close as I can think, and I’d like your opinion.  No, really… I want to hear what you think.  Constructive criticism, please!

What follows is all the information I had included in about a half dozen posts about this idea.  It started to be cumbersome and weird to navigate on the main page, so I’ve copy-pasted all of that info into this one page.  Where there were blog post titles for navigation, I’ve simply bolded and italicized and used a larger font.

Admittedly, this is all a LOT of information to digest, but considering Armor Class has been around since the very early days of Dungeons and Dragons, and it’s built into just about everything in the game, there is a lot to consider when thinking about removing and replacing it.

NOTE: There are about a zillion feats in D&D that affect or are affected by Armor Class.  Most should be easy to convert to O.R.C., but some will not.  As the DM, you’ll have to make calls on a case by case basis.  That’s why you get paid the big bucks, right?

As of right now (October 26, 2017) this system has not yet been playtested by me or anyone else I know, so if you do use this and find problems, PLEASE let me know!

I hope someday to take all of this info and put it into one, cohesive book for ease of use, but in the meantime, I present to you:

O.R.C. Opposed Roll Combat

Chapter 1: The Basics

Alternate Armor and Combat Rules for Dungeons and Dragons

As an alternative to armor class ratings, O.R.C. is based on opposed roll combat, which is to say that every attack roll faces a defensive roll by the defender.

When attacked, a defender now has three options: Parry, Block, or Dodge

Every attack roll is now treated as a DC for a defense roll.  If an attacker rolls a grand total with all bonuses equal to a 17, the defender must match or exceed that number to avoid being hit.

PARRY: A defender can PARRY a number of attacks equal to the number of attacks the defender has each round, i.e. a first level character usually has only one attack per round, so can only parry one attack without losing their own attack.  The defender may, if she has not already attacked, sacrifice her attack to PARRY an additional attack.

To PARRY, the defender rolls a d20 plus all attack bonuses, just as if she were attacking, and attempts to match or beat the attackers roll.  If successful, the attack does no damage.  If not successful, the defenders armor (if any) absorbs some amount of the damage (covered later in this document).

BLOCK: A defender can BLOCK an attack if she has a shield.  The defender can BLOCK a number of attacks equal to her DEX modifier, minimum of once.  The defender can NOT sacrifice her attack for any additional BLOCKS.  To BLOCK an attack, the defender rolls d20 plus STR modifier, plus the armor class bonus of the shield (usually +1).  If the STR modifier is a negative number, it is applied as a negative to the defender’s roll.

DODGE: A defender’s last resort is to DODGE.  A defender can dodge any number of attacks.  To DODGE, a defender rolls d20 plus DEX modifier.

Critical attacks (natural 20) can only be defended against with a natural d20.  In this case, the attack and defense are compared for highest total.  If the attacker does roll higher, the amount of damage is increased just as before.


Upon a successful attack that bypasses the defender’s attempts, the attacker rolls damage.  The defender now rolls the armor’s Armor Rating (AR) and subtracts that amount from the damage.  Any remaining damage is subtracted from the defender’s Hit Points.  Every individual suit of armor also has a maximum amount of damage it can absorb before being too damaged to be useful.  This is represented by its Durability Rating (DR).   Any damage that is absorbed by the armor is subtracted from its DR.  The armor cannot absorb more damage than it has remaining DR, so if it gets too beat up it will have to be replaced.


ARMOR                     TYPE              OLD A.C.       A.R.                D.R.

Padded                      Light             +1                    1d6(2)              24

Leather                      Light             +2                    2d6(4)              48

Studded Leather      Light             +3                    3d6(6)                72

Chain Shirt                Light             +4                    4d6(8)                96

Hide                            Medium        +3                    3d8(6)              96

Scale Mail                   Medium       +4                    4d8(8)              128

Chain Mail                  Medium       +5                    5d8(10)            160

Breastplate                  Medium       +5                    5d8(10)           160

Splint Mail                  Heavy            +6                    6d10(12)        240

Banded Mail               Heavy             +6                    6d10(12)       240

Half Plate                    Heavy             +7                    7d10(14)       280

Full Plate                     Heavy             +8                    8d10(16)       320

Magical Armor increases the number of dice rolled as A.R. by the magical bonus, and increases the D.R. by a multiple of its bonus.  For example, a suit of +3 Full Plate would roll 11d10 as A.R. and be able to absorb a total of 960 points!  Armor with a bonus of +1 adds 50% to each rating, rounded down.  For example, +1 Chainmail would be at 7d8(14) and a DR of 240.

This is already a more complex system of combat, so for simplicities sake, Shields have no limit on use.  They’ll just last a long time.  Unrealistic, but no more so than the existing system of everything lasts forever.

Each type of armor does have a minimum amount of damage that it will absorb at no cost equal to the minimum amount of A.R that can be rolled, doubled (in parenthesis after each A.R rating in the table above).  For example a suit of Padded armor can absorb an attack of only two points without losing any D.R.  Any attack of three points or more are treated regularly.  A suit of Full Plate can absorb any attack of 16 points or less at no loss to it’s D.R.  The magical +3 Full Plate can take any attack of 22 points or less.

NOTE: Called Shots (+4 to the TN) become much more relevant in this system.  Head shots are more difficult, but unless the baddie’s got a helmet on, his armor is ignored!

“But What About…”

Chapter 2: Some Details

So let’s go over some issues you’ve probably noticed about Opposed Roll Combat (O.R.C.).  Here’s some questions I think you’re asking:

  • So what about creatures with a natural armor class from tough hide, scales, etc? You can do one of two things.  First the easy way.  Just keep the A.C. and proceed as normal.  Two, give them an A.R. based on their A.C.  For example, a medium Basilisk has a +7 to its armor class due to thick, spiny hide.  You can use that +7 to give it the same basic stats as half plate armor.  The only difference is that it doesn’t have a maximum number of damage points it can absorb.  Every time the basilisk is hit, the GM would roll 7d10 and subtract that amount from the damage.  Luckily, the basilisk can neither parry nor block (unless the GM wanted it to be able to block using its tail…something I wouldn’t do) and since it has a -1 DEX bonus, it can barely dodge.  It’s a lot easier to hit, but damn difficult to really cut into.  Called Shots would be especially important against that sort of monster!
  • How do you repair armor? It’s going to need constant maintenance, especially the light armors.  Good question.  The skill Craft, with a specialization in Armor, can be used during rest times to patch holes, fix tears, etc.  The DC for tasks such as this would be equal to 10 plus the old Armor Class of the armor.  For example, splint mail had an A.C. of +6, so the DC to repair it would be equal to 10+6, or 16.  If the roll is successful, the person fixing the armor rolls 1d8 per rank of Craft and adds that back to the A.R.  This task can be completed in just a few hours, or a “short rest” time period.  See the section below for details.
  • How do you parry monster (X)’s attack? This would have to be up to the GM, on a case by case basis, but generally if the creature has a weapon, or a natural weapon that is used like a hand held weapon (like claws on its hand), then a parry would be appropriate.  You might not be able to parry a large tail attack, but I don’t think a block would be out of the question.

That’s all I can think of right now.  I will cover magical repairs soon… I’m sure there’s already some spell or spells out there for fixing stuff, I just gotta figure out how to apply them to O.R.C.

O.R.C. Range Combat 1

Question: So if there’s no armor class (A.C.), then what do we do about ranged combat?

Answer: I’ve taken a look at old-timey RPG’s for the answer to this one.  It’s pretty straightforward, with some modifiers.

When an attacker is shooting or throwing a ranged weapon at an opponent, the base Difficulty Class (D.C.) to hit is based on range to the target, and modified by circumstances.

EDIT: After writing and posting this whole article, it dawned on me that I should make provisions for blocking incoming missile weapons with a shield.  I’ve got to think that through before I add it, so bear with me as you read this.

To hit a man-sized target at medium range that is not moving, not obscured, and in good light, such as an unsuspecting guard standing next to the bad guy’s hideout entrance, the D.C. is a simple 10.  Either you hit him or you don’t, 50/50.

From that point forward, circumstantial and environmental modifiers affect the base D.C. of the attack.  Movement of the target or the shooter, cover or concealment of the target, lighting conditions, and range are some of the typical things that affect the chance to hit.  See the chart below for a sampling.

The attacker gets to roll to hit as per the normal rules, i.e. d20 plus their Dexterity bonus and whatever magical or masterwork bonuses, or feat or other bonuses they might have.  If the roll higher than the modified D.C., they have hit their target.

One of the most important modifiers that must be considered is dodging.  Dodging with this system is NOT a reactive roll, which is to say the defender does not get to roll to dodge after the attacker rolls.  If a character wishes to be more difficult to hit through movement or dodging, that character needs to state that they are dodging during their own action.  If they don’t state that they are moving from point to point, or going “serpentine” and dodging and weaving, then they are not considered to be more difficult to hit than any other moving target.

For example, my 4th level fighter is crossing the altar room in an underground temple on his way to attack the goblin guards that are shooting crossbows at the party.  On my action, I tell the DM that I’m moving my typical 30 feet towards the enemy, drawing my sword as I move.  The goblin crossbowmen will have a negative modifier to their chance to hit me, but only based on speed.  If instead I tell the DM that I’m ducking and weaving (something I can’t do if I’m charging), the goblins will get a negative modifier based on movement AND another negative mod for the dodging.  In other words, I’m actually working to make myself harder to hit.

It’s up the target to make sure he’s a hard target to hit.

Now let’s take a look at some modifiers.  These are all based on my best guess and experience with similar systems in different RPG’s, so feel free to change these modifiers as you see fit.

NOTE: Dungeons and Dragons 3.5 and higher assign a range increment to every ranged weapon.  In the context of O.R.C., that range increment is considered effective range.  One half of effective range is close range, and one half of close range is point blank.  Effective ranged doubled is long range, and long range doubled is extreme range.  Maximum possible range is the outer limit of Extreme range.

For example, a longbow has a range increment of 100’.  With the O.R.C. system, the range increments for that same longbow are as follows:

Point Blank                   25’

Close Range                 26-50’

Effective Range            51-100’

Long Range                  101-200’

Extreme Range             201-400’

Dungeons and Dragons 3.5 and higher do not increase ranges of composite bows based on high strength, so that is not changed in O.R.C.



Point Blank                   -4

Close Range                 -2

Effective Range            +0

Long Range                  +4

Extreme Range             +8


Standing                       +0

Crawling                      +3

(Crossbows and one handed ranged weapons can be used while crawling, but not bows)

Walking                       +2

Running                       +6

Sprinting and Dodging not allowed with ranged weapons, unless the DM wants to assign some serious negative modifiers and give you a chance.


Standing                       +0

Prone                           +2

(Prone is laying down without moving)

Crawling                      +3

Walking                       +1

Running                       +4

Sprinting                      +6

Dodging                       +Target’s DEX bonus plus movement modifier

NOTE: If the target has a negative DEX bonus, it does not apply here.  They can’t “dodge into the arrow”

LIGHTING CONDITIONS (based on normal, unmodified visual sense)

Pitch Dark, no visibility to target           +8 Wild Shot: straight D.C. of 18 with no modifiers

Torchlight                                            +6

Moonlight                                            +4

Dawn/Dusk                                          +2

Normal Daylight                                   +0

Glare or Flare                                        +4


NOTE: Cover means hard cover that will prevent a ranged weapon from penetrating, like a wall or door.  Concealment hides a target from vision, but doesn’t do a lot to prevent the weapon from penetrating, like a bush.


25%     +1

Example: knee high wall or log, or target is only partially around the corner

50%     +3

Example: waist or gut high wall, or target is mostly around the corner

75%     +5

Example: Target visible through a window or battlement

Concealment (a target concealed is a target that has been seen, just not clearly)

25%     +1

Example: target is standing behind a low bush

50%     +2

Example: target is in a tree

75%     +3

Example: target is camouflaged in that tree


Light Rain        +1

Heavy Rain      +3

Light Wind       +4

Heavy Wind     +6

Haze or Fog      +1

Heavy Smoke   +3

Here’s an example of O.R.C. ranged combat in action.

An Elf Ranger has spotted the enemy encampment from concealment and is about to shoot the unsuspecting guard.  It is nighttime, but there is a full moon and the guard is visible.  Neither the Elf nor the guard are moving, but the guard is 175’ away (long range) and the guard is wearing hide armor.  The ranger has bonuses equal to +5 to hit with his longbow, and a +4 on damage.

Base D.C.=       10

Moonlight        +4

Long Range      +4

Total D.C.=      18

The Ranger rolls a d20 and gets a 12.  With his bonuses, his total comes out to a 19, which means a hit.  The guard had no idea he was about to get shot, so he cannot block or dodge the arrow, so the damage roll of 1d8+4 (10) goes into the guards hide armor.  The guard rolls his A.R. of 3d8 and scores 15.  All 10 points are absorbed by the hide armor, which now has 86 points of D.R. left.  The guard is alerted, the encampment comes alive like a nest of ants, and the ranger realizes that he may have made a mistake coming here alone.  Oops.

O.R.C. Ranged Combat Update: Shields

This update is to include the use of shields to block incoming missile fire attacks in O.R.C. ranged combat.

If a target of an incoming missile/projectile attack has a line of sight on the attacker, a shield at the ready, and is not currently distracted (i.e. already in melee combat with someone else), they may try to block the incoming weapon with the shield.

Shields are generally much larger in cross section of any type of missile weapon such as an arrow, spear, dagger, etc, so the defender only has to place the shield generally in the area that the missile is coming from.  This is represented by a bonus to block the weapon.

After a missile weapon’s successful to-hit roll, the defender may roll d20 plus DEX modifier plus the following modifier based on the shields size.  If the defender’s roll exceeds the attackers to-hit, then the shield absorbs the weapon.  The arrow or spear stick into the shield or bounce off.

NOTE: This attempt to block an incoming attack uses up one of the allowable blocks by the defender (equal to their DEX bonus, with a minimum of one) for that combat round.

BUCKLER       +1

LIGHT             +2

HEAVY           +3

TOWER           +5

These bonuses do not include any magical/masterwork type bonuses of the shield.  For example, if you are defending with a +2 magical heavy steel shield, your total bonus on the block roll would be +5.

Remember that a defender must have line of sight, a ready shield, and not currently in hand to hand or melee combat to be able to attempt to block incoming fire.

Again, PLEASE comment or critique, or better yet, play test this stuff!

NOTE: As I said before, Called Shots (+4 to the TN) become Much more relevant when using O.R.C.  Unless your target is wearing a helmet, a head shot ignores armor.

O.R.C. : The Numbers

If you’re wondering how I came up with the numbers for AR and DR in my Opposed Roll Combat (O.R.C.) system, or if you’ve got a type of armor that isn’t on the armor table in that blog post, it’s pretty easy to determine it’s numbers.

The first thing to look at is the Armor Class rating. That number determines how many dice are used for the Armor Rating (A.R.). The class of armor (light, medium, heavy) determines what type of die is used. Light armor uses d6’s, medium armors use d8, and heavy armors use d10.

As stated earlier, to figure out the amount of damage an armor can take without actually losing any points is equal to the minimum that could be rolled, doubled. For example, Chainmail has an A.R. Of 5d8. The minimum that could be rolled is 5, and doubled is 10. Chainmail can take up to 10 points of damage from a single attack without losing any of it’s Durability Rating (D.R.)

Calculating the total D.R. is also easy: the maximum roll possible with it’s A.R., times four.  For example, Chainmail’s A.R. is 5d8.  The maximum possible roll is 40.  Multiply 40 time 4, and you’ve got 160.

So, in effect, the Armor Class determines the number of dice, the type of armor determines the type of dice, and the maximum possible roll determines the damage resistance (D.R.).  Easy, right?

Any creature with a natural AC would be converted using this same system, but natural armor classes do not have a durability rating.  As such, they also do not have a minimum amount of damage that they can take without losing any of their D.R.  An example would be the Assassin Vine. It’s armor class according to the Monster Manual is an 15 but that includes it’s Size modifier. If you take the +6 from it’s natural AC, that would make it the equivalent of Splint or Banded mail. The assassin vine would roll 6 dice, but since it is a natural armor, it is considered Medium Armor, so the vine would roll 6d8.  The Assassin vine would roll 6d8 every time an attacker successfully damaged it, and the amount rolled is considered to be absorbed by the thick… whatever a vine has.

That’s an important point I forgot to point out earlier. Natural Armor is considered Medium, so the die type is a d8, unless the DM changes it to reflect tougher or weaker opponents.

O.R.C. Repairing Damage

According to the 3.5 Players Handbook, the appropriate skill used to repair armor is a Craft Skill, specifically Craft: Armorer. The DC for repair is 10 + the AC bonus.

In the O.R.C. System, it would be the same thing, or 10+ the number of dice used for the A.R., which is the same as the AC rating in D&D. For example, Hide armor has a D.R. of 3d8, and an AC bonus of +3. Therefore the DC to repair Hide armor would be 13.

However, in the O.R.C. System, successful Craft rolls now result in a variable number of D.R. Points being restored to the armor. The crafts person, upon successfully beating the DC, would roll 1d8 for each rank in the Craft skill. For example, let’s say that one of the characters in the group has Craft: Armorer at rank 5. After succeeding at the DC roll, she would then roll 5d8 and that result would be added back to the damaged D.R. Of course, that can not bring the armor to a level higher than its base.

Skill Synergy: If the crafts person also has at least five ranks in crafting the type of material that the armor is made of (for example, leather-working for leather and metal-working for chain and plate, etc.), then she would roll d10’s. In our example above, the armor repair character would roll 5d10.

TIME: Depending on the type of armor, the amount of damage, and the tools available, repairing armor can take as little as a few minutes patchwork repair, or several hours.  For simplicity’s sake, if attempts to repair the armor are “around the campfire”, i.e. while resting but nowhere near a town or a blacksmith’s shop, any suit of armor that still has at least one half of its remaining D.R., it can be repaired in about two hours.  If the armor has gotten below half, this requires extensive repair, and would take a “full rest” (in Fifth Edition) to repair, or about eight hours.  That’s just for one suit of armor.  Whenever the party has a few minutes to stop and take their breath, the armor repair person in the group can do some simple patch-work that can restore a number of points equal to her Intelligence modifier in d4’s (minimum 1).  For example, after a horrendous beating at the hands of an Ogre Magi, the team takes a breather while on the run.  The group’s Rogue takes a few minutes to look them over, and sees that the Cleric’s and the Bard’s armors are pretty beat up.  There’s no time to do an armor-off repair, but he can take a moment to fix up some of the damage.  His Intelligence modifier is a +3, so he rolls 3d4 for a total of 9 points.  The Cleric adds 9 to his D.R.  Another look-see of the Bard’s armor results in a roll of 5.  The Bard adds 5 to his D.R., and hopes that he can sing his way out of the next brutal encounter.  This type of repair only take 1 full turn (10 rounds, or about a minute per set of armor).


All of that assumes that the person repairing the armor has both Artisan’s Tools (PH, page 129) and materials needed to replace worn or broken parts. The minimum amount of necessary materials is equal to 10% of the cost of the base type of armor (before any enhancements). For example, the base cost for ordinary Splint Mail is 200gp. Therefore, the repair person would have to have at least 20gp worth of spare splint mail material. Weight of spare supplies is equal to 5% of the weight of the armor.

Most armorer’s shops have such material on hand, and the GM need not fret with exactly how much the town armor guy has in the supply shed. It’s really only important to track what materials the PC group is bringing with them.

I believe most GM’s can just ignore the requirement for materials on hand without upsetting the balance, but I would suggest that if these rules are used, the repair person should be allowed to roll d4’s instead of d8’s if they do not have any/enough resources, but at least have an Artisan Toolkit.

O.R.C. Magical Repair of Armor,


“When The Mage is Finally Worth Having Around”

Considering how often your typical adventurer gets into conflict (pretty damn often), her armor is gong to regularly need repair. When the group is seven levels down into the Tomb of Horrors, there’s no time for lengthy mundane repairs. She needs the Wizard to step up and do her bippity-boppity-boop thing and get her chain-mail repaired right freakin’ now!

Luckily for her, the Wizard isn’t offended by her usual theatrics, and has a spell or two prepared for just such an occasion.

NOTE: These spells DO work on magical armor just like mundane armor, per the Dungeons Master’s Guide (3.5) page 214. Since magical armor has quite a bit more D.R. than regular armor, you would multiply the results of the spell’s damage repair roll by the the bonus, just like how you determine the D.R. of magic armor in the first place.

Minor Armor Repair


Level: Sor/Wiz 1, Bard 1

Components: V/S/M(F)

Casting Time: 1 standard action

Range: Touch

Target: 1 set of armor per round spell duration

Duration: Concentration

Saving Throw: N/A

Minor Armor Repair can be cast on a single set of armor, and will repair an amount of Damage Resistance points equal to the Caster’s level plus spell slot level used in d10’s. For example, a first level Wizard casting this as a first level spell would roll 2d10, while a third level Wizard using a second level spell slot would roll 5d10. Since 3.5 does not use spell slots (unless the DM house rules that… and I think they should. It’s an excellent concept), it would be the Wizard (or Sorcerer’s) level plus 1. The spellcaster can keep this spell active long enough to affect each armor worn by his nearby companions while concentrating, but each set of armor can only be affected once. The material component of this spell is a small silver hammer

Major Armor Repair


Level: Sor/Wiz 2, Bard 3

Components: V/S/M(F)

Casting Time: 1 standard action

Range: Touch

Target: 1 set of armor per round of spell duration

Duration: Concentration

Saving Throw: N/A

Major Armor Repair is the big brother of Minor Armor Repair, but instead of repairing a random number of D.R. points, Major Armor Repair will repair 75% of the D.R. lost, regardless of how much that might be. This can also be used only once per set of armor, but can be used repeatedly as long as the caster concentrates. The material component of Major Armor Repair is a small ornamental silver helmet-shaped amulet worth at least 1000g.p.

Armor Restoration


Level: Sor/Wiz 3, Bard 4

Components: V/S/M

Casting Time: 1 full turn

Range: Touch

Target: A single set of armor only

Duration: Instant

Saving Throw: N/A

Armor Restoration will repair one set of armor, regardless of condition, magical bonuses, or material used, to a like-new condition, with full D.R. It will also look and feel brand new, so much so that you probably want to have a can of oil on hand, or you’re going to be a bit squeaky/clanky for a while. Metal armor will gleam like it’s fresh off the polisher’s block, and leather armor will have that “new car” smell. The material component of this spell is a bar of pure platinum worth at least 5,000g.p.