Ars Certo

Copyright Peter Mork © 2011

"...playing a warrior should require selecting the right tactic from a similarly expanding set of options"

Ars Certo

As mages gain levels, their repertoire of spells grows accordingly; playing a mage requires selecting the right spell from an ever-growing set of options. As warriors gain levels, their offensive bonus gets bigger.

This article provides a number of optional rules for combat (especially melee combat). The ultimate goal is to allow warriors to gain new tactical options as they advance in level; playing a warrior should require selecting the right tactic from a similarly expanding set of options.

Defensive Options

New Skills

Normally, when a character is attacked, his defensive bonus is based on 3 × Qu. Thus, there is no mechanism for a character to increase his DB apart from parrying (or learning Adrenal Defense, which has a host of restrictions).

Using Ars Certo, we add a new skill category: Mundane Defenses (Qu/Qu, 0•0•0•0•0). This category costs 3/8 for all professions. It includes the following new skills.

  • Dodge (Qu, 0•1•1•0.5•0): This skill determines the character's DB against any attack of which he is aware. It replaces the normal formula for DB (although a character with no ranks of Dodge will have a DB of 3 × Qu like normal).
  • Parry (In, 0•2•1•0.5•0): This skill determines the character's DB when parrying an attack. The character's DB is increased by the amount allocated to parry, plus the parry modifier for the item (5 for most weapons).
  • Shield (Ag, 0•2•2•1•0.5): This skill determines the character's DB when using a shield against an attack. The character's DB is increased by the shield modifier for the item (20 or more for most shields).

Option: If you prefer not to modify a character's core DB, the stat for each skill remains Qu. This prevents Ag and In from becoming even more important.

When multiple skills apply (e.g., a character is parrying and using a shield so all three skills apply), the player may choose which base DB to use (Dodge, Parry or Shield). The character's DB is still increased by any modifiers (including allocating OB to DB, shield/parry modifiers, etc.).

Example: Galion has +5 Qu, +2 Ag, +8 In, 12 ranks of Dodge, and 8 ranks of Parry. Thus, his Dodge skill bonus is +27, Parry is +34, and Shield is +12. Before he has his sword and shield out, his DB is 27. After readying his normal shield, his DB increases to 47 (he chooses to Dodge, but still gets the +20 bonus from the shield). When he parries with 40, his DB increases to 99 (+34 from Parry skill + 20 from the shield + 40 from parrying + 5 from the sword).

Using a Shield

Non-Actions: In RMSS, a character can declare a maximum of three actions in a round—one for each phase. Because actions are a precious resource, certain activities are considered non-actions. These activities tend to modify another action. For example, parrying is a non-action that modifies an attack by transferring OB to DB. A non-action still takes time (i.e., it consumes some % of the character's activity); it merely does not count against the limit of three actions per round.

Using a shield requires some concentration. During the declaration phase, the player should determine how many attacks he will be blocking with his shield. Each such allocation is a 5% non-action.

Whenever (during the round) that the character is the target of an attack (that does not receive positional modifies), the character can choose to "spend" one shield block to gain the following benefits: a) he can choose to use his Shield skill in place of Dodge and b) his DB is increased by shield modifier for the shield.

Parrying

Defending oneself with a weapon requires even more attention. During the declaration phase, the player chooses how many attacks he will half- or full-parry. Each half-parry is a 15% non-action, and each full-parry is a 30% non-action. However, if the character full-parries even once, he cannot declare any melee attacks.

Whenever (during the round) that the character is the target of an attack (that receives no positional modifiers and can be parried: missile and spell attacks can normally not be parried, but they can be blocked using a shield), the character can choose to "spend" one parry to gain the following benefits: a) he can choose to use his Parry skill in place of Dodge, b) his DB is increased by 50/100% of his OB (for half- and full-parries, respectively), and c) his DB is also increased by the parry modifier for the weapon (usually 5, except for parrying weapons like main gauches).

Each parry is also associated with a phase: Snap deflects can be used against any attack; normal parries can be used against any normal or deliberate attack; and deliberate blocks can be used only against deliberate attacks. Thus, an attacker can bypass a normal parry by declaring a snap attack. However, parry non-actions are not affected by initiative. Once the normal phase starts, a parry is effective, even if the defender lost initiative to the attacker. The modifiers for speed (-20/0/+10) and item are applied before halving the character's skill.

Example: Galion has +75 skill with a broadsword. When he half-parries (a normal speed non-action), his DB is 74 (+34 from Parry skill and (+75 broadsword + 5 parry modifier) / 2). When he full-blocks (a deliberate speed non-action), his DB is 124 (+34 from Parry skill + 75 broadsword + 5 parry modifier + 10 deliberate).

Option: When calculating a character's skill with a weapon, do not include any material bonuses (e.g., high steel or Laen). These bonuses only apply to attacks made with the weapon.

Armor

When a character is attacked, there is a chance that his armor absorbs the damage (armor includes any AT of 5 or greater). An attack that bypasses armor affects the target normally. An attack that is absorbed damages the target's armor (instead of the target). For normal armor, roll d100 and add 20 + 2 × AT; for magical armor, add 30 + 3 × AT. A simple leather jerkin absorbs damage 30% of the time, while magical full plate absorbs damage 90% of the time.

Armor points and damage are calculated as in Arms Law. A suit of armor has 50 × AT + 20 × DB armor points. Concussion hits are converted to armor damage directly; criticals inflict armor damage equal to 10 × severity. For example, if armor absorbs a 14C, the armor takes 44 points of damage.

As armor takes damage, it loses its ability to absorb high-severity criticals. Once a suit of armor has lost 20% (or more) of its armor points, it can no longer stop E criticals (i.e., any attack that results in a E critical automatically bypasses the armor). For every additional 20% damage, the armor's ability to stop criticals is reduced by one. For example, a leather jerkin (250 armor points) that has taken 50 armor points cannot stop E criticals. After 100 armor points it cannot stop D or E criticals. And, after sustaining 250 armor points, it cannot absorb any damage whatsoever.

Offensive Options

New Skill Categories

Since the inception of Rolemaster, two-handed weapons constitute a category unto themselves. Thus, a (two-handed) flail is considered more similar to a two-handed sword or quarterstaff than it is to a ball and chain. In Ars Certo, there are fourteen weapon categories (instead of seven). Each weapon cost now corresponds to two categories. For example, a Rogue can learn two categories at a cost of 2/5, two more at 3/8, six more at 3/9, etc.

Category Examples Stats Category Progression Skill Progression
Weapon • Artillery, Direct Crossbow, Ballista Ag/In/In 0 4 1 0 0 0 2 1 0.5 0.5
Weapon • Artillery, Indirect Catapult, Trebuchet Ag/In/Re -30 2 2 1 0 0 2 2 1.5 0.5
Weapon • Bow Longbow, Slingshot Ag/St/Ag -15 3 1.5 0.5 0 0 2 1.5 1 0.5
Weapon• Chains Whip, Flail, Net Ag/Ag/St -30 2 2 1 0 0 2 2 1.5 0.5
Weapon • Chopping Axe, Hammer St/Ag/St -15 3 1.5 0.5 0 0 2 1.5 1 0.5
Weapon • Crushing Mace, Club St/St/Ag 0 4 1 0 0 0 2 1 0.5 0.5
Weapon • Energy Pistol Blaster, Phaser Ag/In/Ag -15 3 1.5 0.5 0 0 2 1.5 1 0.5
Weapon • Energy Rifle Blaster, Phaser Ag/In/Ag 0 4 1 0 0 0 2 1 0.5 0.5
Weapon • Pole Arms Spear, Pole Axe St/Ag/St -30 2 2 1 0 0 2 2 1.5 0.5
Weapon • Powder Pistol Handgun Ag/In/St -15 3 1.5 0.5 0 0 2 1.5 1 0.5
Weapon • Powder Rifle Musket Ag/In/St 0 4 1 0 0 0 2 1 0.5 0.5
Weapon • Slashing Sword, Falchion St/Ag/St -15 3 1.5 0.5 0 0 2 1.5 1 0.5
Weapon • Thrown Javelin, Sling Ag/St/Ag 0 4 1 0 0 0 2 1 0.5 0.5
Weapon • Thrusting Rapier, Dagger St/Ag/Qu -30 2 2 1 0 0 2 2 1.5 0.5

With this classification, everybody can use certain weapons without much difficulty: clubs, rifles and (thrown) rocks. Finesse weapons that require some sophistication include chains, rapiers and pole arms. Simple weapons benefit more from category bonuses, but finesse weapons can ultimately result in larger OBs.

Attack Maneuvers

In RMSS, whenever a melee attack is declared, the player must choose from among nine options based on attack speed (snap, normal or deliberate) and attack type (full, pressing or react). These options are available to all characters, at all times. Using Ars Certo, a character must learn each of these nine options (plus the three parrying options listed above). Thus, each weapon category is associated with twelve basic maneuvers, plus one or more special maneuvers.

All characters start with two maneuvers for each category, usually the normal pressing and defensive maneuvers (forehand and parry for most weapons). For every two ranks the character develops in the appropriate category, he learns one new maneuver. For example, a character with 8 ranks in Weapon • Chopping knows a total of six attack maneuvers. After 20 ranks, the character learns one new maneuver for every five ranks, to a maximum of 14 maneuvers with 30 ranks.

Note that many maneuvers appear in multiple categories. For example, Forehand is a valid attack maneuver for every weapon category, and Lunge is valid for slashing and thrusting weapons. When a character learns such a maneuver, he can use that maneuver with any weapon for which that maneuver is valid (once you learn to Lunge with a broadsword, you can also Lunge with a rapier).

Example: Bronwyn uses swords and axes. She has 8 ranks of Weapon • Slashing and 1 rank of Weapon • Chopping. She currently knows Forehand, Backhand, Overhand, Parry, Lunge and Slash. She can use any of these maneuvers with a sword and all but Lunge with an axe. When she learns another rank of Weapon • Chopping, she is not able to learn another maneuver because she already knows at least three maneuvers applicable to the Weapon • Chopping category.

Each category also includes at least one special maneuver. To learn a special maneuver, the character must already know all pressing and defensive maneuvers for that category. For example, to learn Riposte, a character must know Deflect/Parry/Block and Backhand/Forehand/Overhand.

Category Phase Type Attack Modifier Description
Martial Arts • Striking Snap Defend Deflect -20 This defense is intended to slow the attacker long enough for the defender to step aside enough to avoid being struck.
Full Stomp -10 The attacker smashes his opponent's feet or legs.
Pressing Knee -20 This is a nasty attack intended to incapacitate the opponent quickly.
React Cuff -30 This is a quick slapping attack.
Normal Defend Parry 0 This defense is intended to knock aside the attacker's blow.
Full Upper Cut 10 This is a powerful shot usually directed at the head.
Pressing Punch 0 This is a quick body blow.
React Check -10 Given an opening, the attacker slams into his opponent with his shoulder or hip.
Deliberate Defend Block 10 This defense is intended to stop the attacker's blow completely.
Full Slam 20 This is an intense two-fisted attack intended to propel the defender backwards.
Pressing Kick 10 The attacker aims to impel his foot through the defender's body.
React Elbow 0 This is a vicious attack with the attacker's entire weight behind his elbow.
Any Special Weapon Kata 0 This allows the attacker to use a specific weapon type while attacking.
Knife Kata 0 This allows the attacker to use a knife while attacking.
Martial Arts • Sweeps Snap Defend Deflect -20 This defense is intended to slow the attacker long enough for the defender to step aside enough to avoid being struck.
Full Toss -10 This rapid attack relies on leverage.
Pressing Nudge -20 This is a quick, disorienting attack.
React Jostle -30 This is a quick attack intended to distract.
Normal Defend Parry 0 This defense is intended to knock aside the attacker's blow.
Full Throw 10 This attack uses upper body strength to propel the defender.
Pressing Shove 0 This is a strong blow that forces the defender back.
React Bump -10 The defender is nudged while the attacker passes by.
Deliberate Defend Block 10 This defense is intended to stop the attacker's blow completely.
Full Hurl 20 Leveraging the entire body, the attacker crouches and hurls the defender high into the air.
Pressing Launch 10 This powerful blow sends the defender soaring.
React Trip 0 This attack aims to take the defender's legs out from underneath him.
Any Special Stick Kata 0 This allows the attacker to use a staff while attacking.
Weapon Kata 0 This allows the attacker to use a specific weapon type while attacking.
Weapon • Chains Snap Defend Deflect -20 This defense is intended to slow the attacker long enough for the defender to step aside enough to avoid being struck.
Full Lash -10 This is a quick, single crack of the weapon. It causes extreme pain to an unsuspecting opponent.
Pressing Backhand -20 This blow originates from the extended position. The attacker spins the weapon over his head and attacks the defender's weapon side.
React Flick -30 This quick, light attack tends to annoy and frustrate the defender. The attacker's wrist delivers the impact.
Normal Defend Parry 0 This defense is intended to knock aside the attacker's blow.
Full Flog 10 This is a series of several lashes. The marks it leaves are distinctive.
Pressing Forehand 0 This blow originates from the neutral position. The attacker swings the weapon at the defender's shield side.
React Slap -10 This attack relies on a stiff wrist and bent elbow to deliver a painful, stunning blow.
Deliberate Defend Block 10 This defense is intended to stop the attacker's blow completely.
Full Scourge 20 This is a relentless series of blows. If successful, the defender is left broken and bloody.
Pressing Overhand 10 This is a powerful blow from the neutral position swung over the attacker's head.
React Smack 0 This attack combines the unpredictability of a flexible wrist with the power of sweeping arm motion in an attempt to bowl over the defender.
Any Special Snare 0 This maneuver snares the defender's weapon/shield. All of the defender's remaining defenses (with that item) are declared versus this attacker. (40% action)
Weapon • Chopping Snap Defend Deflect -20 This defense is intended to slow the attacker long enough for the defender to step aside enough to avoid being struck.
Full Gouge -10 This quick, powerful attack is usually directed at the body. Twisting or lifting the end of the weapon causes additional damage.
Pressing Backhand -20 This blow originates from the extended position. The attacker spins the weapon over his head and attacks the defender's weapon side.
React Scratch -30 This quick, shallow attack is intended to bypass all defenses. It is painful, but usually superficial.
Normal Defend Parry 0 This defense is intended to knock aside the attacker's blow.
Full Gash 10 This attack requires the attacker to rotate his body as he aims to expose one of the defender's organs.
Pressing Forehand 0 This blow originates from the neutral position. The attacker swings the weapon at the defender's shield side.
React Slice -10 This slicing motion can easily be parried by an alert defender. It is most effective after the defender has committed his parry.
Deliberate Defend Block 10 This defense is intended to stop the attacker's blow completely.
Full Cleave 20 This power strike focuses all of the attacker's body into a massive attack aimed at cutting the defender in two.
Pressing Overhand 10 This is a powerful blow from the neutral position swung over the attacker's head.
React Slash 0 This is a large sweeping motion intended to split open the defender. When it connects, it is very painful.
Any Special Snag 0 This maneuver pulls down the defender's defenses. All of defender's shield defenses are lost. (20% action)
Weapon • Crushing Snap Defend Deflect -20 This defense is intended to slow the attacker long enough for the defender to step aside enough to avoid being struck.
Full Bash -10 This quick, powerful attack is usually directed at the body. It raises large welts.
Pressing Backhand -20 This blow originates from the extended position. The attacker spins the weapon over his head and attacks the defender's weapon side.
React Tap -30 This is a quick wrist attack intended to disorient. It is hard to defend against.
Normal Defend Parry 0 This defense is intended to knock aside the attacker's blow.
Full Smash 10 This attack requires the attacker to rotate his body as he aims to shatter one of his opponent's joints.
Pressing Forehand 0 This blow originates from the neutral position. The attacker swings the weapon at the defender's shield side.
React Jab -10 This attack relies on elbow strength to whittle down an opponent.
Deliberate Defend Block 10 This defense is intended to stop the attacker's blow completely.
Full Roundhouse 20 This blow originates from the extended position. The attacker swings the weapon around his entire body (while extended) before slamming into his opponent.
Pressing Overhand 10 This is a powerful blow from the neutral position swung over the attacker's head.
React Strike 0 This attack combines elbow and wrist flexibility to deliver a powerful blow.
Any Special Knock Back 0 If the attacker gets a critical, the defender cannot declare a pressing attack the next round. (20% non-action)
Weapon • Pole Arms Snap Defend Deflect -20 This defense is intended to slow the attacker long enough for the defender to step aside enough to avoid being struck.
Full Gouge -10 This quick, powerful attack is usually directed at the body. Twisting or lifting the end of the weapon causes additional damage.
Pressing Backhand -20 This blow originates from the extended position. The attacker spins the weapon over his head and attacks the defender's weapon side.
React Poke -30 This rapid thrust is used to keep opponents at bay.
Normal Defend Parry 0 This defense is intended to knock aside the attacker's blow.
Full Gash 10 This attack requires the attacker to rotate his body as he aims to expose one of the defender's organs.
Pressing Forehand 0 This blow originates from the neutral position. The attacker swings the weapon at the defender's shield side.
React Stab -10 This reactive maneuver punishes an aggressive opponent by using his own momentum against him.
Deliberate Defend Block 10 This defense is intended to stop the attacker's blow completely.
Full Cleave 20 This power strike focuses all of the attacker's body into a massive attack aimed at cutting the defender in two.
Pressing Overhand 10 This is a powerful blow from the neutral position swung over the attacker's head.
React Skewer 0 In this powerful thrust, the weapon is propelled by the attacker's own momentum. The opponent's momentum augments the wound.
Any Special Bypass 0 The attacker thrusts from over the shoulder of the person in front of him. (10% non-action)
Weapon • Slashing Snap Defend Deflect -20 This defense is intended to slow the attacker long enough for the defender to step aside enough to avoid being struck.
Full Nick -10 This quick, shallow thrust is performed from the back foot. It tends to yield superficial wounds.
Pressing Backhand -20 This blow originates from the extended position. The attacker spins the weapon over his head and attacks the defender's weapon side.
React Scratch -30 This quick, shallow attack is intended to bypass all defenses. It is painful, but usually superficial.
Normal Defend Parry 0 This defense is intended to knock aside the attacker's blow.
Full Stick 10 This thrust transfers weight from the back foot to the front. The attacker aims to place the weapon well into his opponent.
Pressing Forehand 0 This blow originates from the neutral position. The attacker swings the weapon at the defender's shield side.
React Slice -10 This slicing motion can easily be parried by an alert defender. It is most effective after the defender has committed his parry.
Deliberate Defend Block 10 This defense is intended to stop the attacker's blow completely.
Full Lunge 20 This large thrust requires the attacker to step forward. The attacker aims for a point behind (through) his opponent.
Pressing Overhand 10 This is a powerful blow from the neutral position swung over the attacker's head.
React Slash 0 This is a large sweeping motion intended to split open the defender. When it connects, it is very painful.
Any Special Rap-Shot 0 The attacker steps forward and hooks his weapon around his opponent. The attacker raps the back of the defender's head. (10% non-action, can only be defended by earlier modes)
Weapon • Thrusting Snap Defend Deflect -20 This defense is intended to slow the attacker long enough for the defender to step aside enough to avoid being struck.
Full Nick -10 This quick, shallow thrust is performed from the back foot. It tends to yield superficial wounds.
Pressing Backhand -20 This blow originates from the extended position. The attacker spins the weapon over his head and attacks the defender's weapon side.
React Poke -30 This rapid thrust is used to keep opponents at bay.
Normal Defend Parry 0 This defense is intended to knock aside the attacker's blow.
Full Stick 10 This thrust transfers weight from the back foot to the front. The attacker aims to place the weapon well into his opponent.
Pressing Forehand 0 This blow originates from the neutral position. The attacker swings the weapon at the defender's shield side.
React Stab -10 This reactive maneuver punishes an aggressive opponent by using his own momentum against him.
Deliberate Defend Block 10 This defense is intended to stop the attacker's blow completely.
Full Lunge 20 This large thrust requires the attacker to step forward. The attacker aims for a point behind (through) his opponent.
Pressing Overhand 10 This is a powerful blow from the neutral position swung over the attacker's head.
React Skewer 0 In this powerful thrust, the weapon is propelled by the attacker's own momentum. The opponent's momentum augments the wound.
Any Special Riposte 0 This 0% action allows the attacker to declare 5% defenses.