Shapers is a game in which players play individuals called the Willful, who are creatures possessed of exceptional natural abilities and the ability to reshape reality through the force of their wills. They possess these abilities because of their strong connection to the force of Fate or Destiny, which binds them as much as it empowers them. What I'm wondering is if the task resolution mechanics that I've designed fit the style of game that I'm going for. Which, to be clear is:

*A 40/30/30 mix of Narrativism, Gamism and Simulationism. Players should compete with one another to see their character's visions of how the world should be realized (Step On Up), should be relatively balanced with each other (Step On Up) and their actions and characters should fit the world that the players and GM cooperatively create through a world-creation minigame (The Right to Dream). Where the Narrativism comes in is answering the basic question posed by this game: How will you change the world, and how will you deal with the consequences?
* Gritty/Cinematic in tone. Characters won't be able to just shrug off problems, but with cunning and judicious use of their abilities can overcome what the "real world" throws at them.
*Moderately Complex. Allows for some granularity, but doesn't get bogged down in minutiae
*Emphasizes creative thinking and skill in task resolution.

With that being said, here are my task resolution mechanics in a nutshell:

A "check" is defined as: 2d10+Modifiers which is then compared against a target number.

Success (and in some cases Failure) is based on a sliding scale, with every 2 points that the roll exceeds the target number counting as a "success" which increases the primary function of the action (like movement speed, damage, the persuasiveness of an argument, or the potency of spell) and every 1 point that the roll exceeds the target number adding to the secondary function of the check (typically duration). The same rule is applied to those rolls which have standards for failure: every 2 points below count as a failure, and every 1 point counts as a mark against you.

There are 4 types of checks, each using a descriptor for Opposition, and Duration.

Opposition Descriptors:

Unopposed: These are checks not made against an active force or another character. These are made against a static TN determined by the GM and modified by circumstances.

Opposed: These are checks made against an active force or another character. Each character rolls a check, with the defending character always having the option of taking a result of 10 (this speeds up play and gives skilled characters an edge on defense). The defenders result becomes the TN for the check.

Duration Descriptors:

Instant: This is a single discreet action, such as making an attack, jumping a gorge, reshaping reality etc. It requires only one check.

Prolonged: This is a series of checks, often with different skills or abilities against varying TNs. The goal is to get a certain number of successes before a certain number of failures (set by the GM based on the circumstances), and in the case of Opposed Prolonged checks to become successful before your opponent (or else to cause him or her to fail). Any skill or ability can be used that can be justified to the group (determined by a group vote if there's contention, with the GM serving as tiebreaker), with the GM providing modifiers called "tags" that give advantages and disadvantages to various types of checks.

Tags
Tags are modifiers to various checks that provide perks or drawbacks to the check involved. For example, the GM might determine that all spells cast in a demon-tainted shrine have the "attracts attention" tag, which means that each one cast has the chance of attracting the attention of a hostile or mischievous force. Tags can be applied by either the GM (based on his or her determination of factors influencing a die roll) or by players through their character's actions and abilities. A character might have, for example an ability that grants all physical skills he or she possesses have the "Impressive" tag, which gives a character who performs one successfully a bonus to social skill rolls against individuals who witnessed the "Impressive" skill.

Effectiveness and Ease

Two of the most common "tags" that can be applied by players and GMs are effectiveness and ease. These are gained by players by using equipment, casting spells, creating good circumstances etc. and applied by the GM based on his or her determination of how surrounding factors influence a check. Effectiveness either adds successes to a successful check or subtracts successes from a check (potentially adding failures), whereas ease applies a numerical bonus or penalty to the check.

That's basically the system in a nutshell. Tell me what you think, along with any ideas you might have for expanding the system or improving on it.

In my opinion, the resolution mechanic is meaningless without its applicable context (i.e. the subsystems which it is applied).  Can you give us some examples of the resolution mechanics in use?  I particularly would like to see how the double-layered margin of success/failure concept works.

Alright-here's a straightforward example: Combat. Rules Text will be italicised

Sir Augustine is a chivalrous Willful who is a knight of the fabled order of the golden serpent. His defining Virtue is Chivalry, his defining Flaw is Pride, his goals are Unite the realms of Man, Purge the City of Foolsport of the Criminal Scum that Live there, and to raise up a faithful squire to continue his work should he fail. His Destiny (which he does everything to thwart) is to be corrupted into the service of evil through his own pride and the attentions of a "wolf in sheeps clothing", who he constantly is on the lookout for. Over the course of the Skein, Augustine has acquired the Legendry "Scourge of Thieves" for his conversion of the leader of the Black Asp's thieves cabal, and his ruthless slaying of many of their men. While attempting to fufill one of his goals (Elminate the criminal element in Foolsport) he runs afoul of a local tough, who isn't one of the Willful but who resents Augustine's wealth and sanctimoniousness. He decides to show the knight what happens to do-gooders that snoop around where they aren't wanted.

Augustine is enjoying a glass of wine in a mostly-deserted hole in the wall, reflecting on what he's learned from his contact Skinny Pete the Fence. It's dark enough in the dingy place that the Thug (who we'll call Marid) is going to attempt to sneak up on the knight and knock him upside the head with a crude club. Marid first rolls Stealth+Agility (+5) versus Augustine's Awareness+Perceptiveness (+3). The GM decides that Marid will gain a +2 ease bonus because of the dark surroundings. Marid rolls a 15, for a total of 20, while Augustine rolls a 12, for a total of 15.. That means Marid has 2 successes and 5 marks above Sir Augustine. This means he'll gain 2 points of effectiveness in his attack or other action against the knight, and that if nothing changes to reveal Marid's position (such as him attacking or someone observing him and pointing him out to the knight) he'll be hidden for 5 rounds before he needs to make another Stealth check.

Marid creeps forward with a stealth that belies his considerable bulk (a mixture of fat and muscle). The knight, who seems too deep in thought (and into his wine glass) to notice, just sits there-an easy target.

Marid swings the club with all the force that his sinewy arms can muster, using the "Brute Force" Technique, which adds the "Effective" tag twice, adding 2 points of Effectiveness to the the attack (Adding 2 successes on a successful attack) but which also adds the "Risky" tag twice as well which means that if the attack fails, Marid gains 2 additional Failures. He rolls his Weaponry+Strength+Ease bonus (+7) vs. Augustine's Dodge Defense (Agility+Perceptiveness) which is +5. Augustine chooses to take the average, which is his right as defender (15). Marid botches the roll however, ending up with a total of 9. Augustine has 3 successes over Marid, and 6 marks! He chooses to apply one of those failures to Marid dropping his weapon (and 2 of the Marks, meaning it flies 4 feet away), and two to applying a -2 ease penalty to Marid's Defense (which will last for 4 rounds, due to the marks allocated to it).

Marid raises the club high above his head and lets out a grunt of effort as he brings it down with devastating force. But the grunt alerts Sir Augustine at the last second, who unencumbered by his customary suit of plate, leaps out of the chair and into a defensive stance. The club slams down onto the wooden chair, cracking it in two and sending painful vibrations through Marid's arms causing him to curse and drop the weapon, which slides on the wine, piss, and grease sopped floor to rest beneath the table. Marid's too busy cursing at the pain and his own foul luck to prepare for what comes next.

Sir Augustine could easily take advantage of his foe's mistake, but it wouldn't be in keeping with the personality of the character. Good thing Augustine's defining Virtue is Chivalry, which means that if he acts in a Chivalrous way that causes problems for him (such as giving Marid another swing), he gains a number of Will points (which are used to keep on going despite obstacles) based on the severity of the problem that it causes. The GM determines that since Marid isn't really a match for the Knight in a straight-up fight, that it's only worth 1. Augustine instead stands at the defensive and attempts an Intimidate+Presence (+7) check (using 2 points of his Legendry pool to boost the roll, since Marid is a thief and scoundrel, exactly the sort that a "Scourge of Thieves" should have no problem with). He gets a 17, and uses the 2 points to boost it after he sees the roll-he really wants to prevent bloodshed. Marid takes 10 on his mental defense (Perceptiveness+Intelligence) roll, for a result of 13, subtracting the amount above 10 from Augustine's roll, for a total of 16. This is then compared to Marid's Mental Toughness (Willpower+Presence or +0) which he rolls, trying to avoid becoming cowed by the knight. He gets a 14, for a total of 1 success and two marks for Augustine. Augustine spends his success and converts the two marks into successes to cause Marid to hesitate for 1 round, as he didn't get enough successes to buy Marid's surrender.

Augustine, despite being in full fighting stance, doesn't take a swing at the obviously open Marid. Glowering, and using the power of his considerable Legendry as a scourge of thieves, earned by fate and trial he says "I've felled far more skilled knaves and footpads than you, thug. Take your stick and get out of this tavern, and tell your comrades to put aside their evil ways or I will come for them just as surely as I will beat you where you stand".  Marid, simple though he is can tell that Augustine is deadly earnest, and can feel the power radiating from him, and pauses for a moment, considering his options.

Augustine, satisfied that Marid is no longer attacking him, calmly sets down a few grimy silver pieces on the table, confident that Marid is scared enough and smart enough to avoid taking them. He then begins to walk out of the tarvern. Marid shakes himself off, stunned by his own good fortune and waits till Augustine has left to greedily and stealthily scoop up the silver pieces. The GM has determined the bartender himself is too apathetic to really care-it's late and who cares about a couple of silver pennies when there are thugs involved? Let them get themselves beat to a bloody pulp, so he can collect the money he's due, -and more besides- from their unconscious bodies..

Pretty much what the rules text says.

Augustine is walking out, when his player asks to make an Awareness check to determine if Marid picked up the silver. The GM applies a -2 ease penalty based on the distance he is away from Marid, and from the door inbetween them. Augustine for his part, applies the three remaining points from his Legendry pool to the check. He succeeds, getting a 15 vs. the set TN of 10. This is a check in which stages of success don't matter-he either hears it or he doesn't. He then walks back into the tavern and taps the thief on the shoulder before punching him in the face, choosing to not apply any techniques, which would add tags to the skill. The GM applies a point of effectiveness though-the thief is in a perfect position to take a lot of damage from a punch. Augustine rolls his Unarmed+Strength (+5) vs. Marid's Defense+10 (he's choosing to take 10)-2, or 13. Augustine rolls a total of 23 vs Marid's 13 defense. 5 successes and 10 marks! Augustine applies those 6 successes (5+1 for the circumstances) to damage and the 10 marks to recovery time. Since the damage from a punch is nonlethal, it'll take Marid 10 minutes to naturally recover from the 6 points of damage this will deal. Marid's first wound level has 6 boxes, which means he's now dazed (losing his moderate action, and takes a -1 penalty to all checks.). His injury threshold is 4, so he takes one injury (the GM chooses a limp, which will halve his speed for the duration of the damage)  The fight's not over by any means, but Marid is certainly at a severe disadvantage.

"I told you that I've felled scum that would eat you for breakfast" Augustine says grimly as he thrusts his fist into Marid's bulging gut, causing the thief to curl in on himself like a deflated balloon-hardly able to move. "Who the hell are you." he gasps. "I am Sir Augustine of the order of the Golden Serpent. And you sir, have picked the wrong fight."

(While that's only a short example, it gives you an idea of what I'm going for. The specific mechanics will probably change as I engage in playtesting and editing, but that's the basic layout. Successes and marks are the basic of all checks, whether skills or abilities. Techniques apply tags to checks, either because they're bought with character points or free form because of the character adding negative tags to the check as well. Talents are like spells for mundane skills, using them to accomplish out of this world physical and mental feats (like running non-stop to a faraway city and back, or causing someone to forget why they're angry at you simply by bombarding them with confusing words) through the allocation of successes and marks, and Spells are magic which give you specific magical effects through the allocation of successes and marks. Talents and Spells can be improvised by spending a Will point, or can be bought as permanent additions to a character's arsenal by spending points.)

So just for clarification, tags are modifiers to a particular check such as "Gains bonus successes on a successful check, or gains bonus successes when a check is successful under certain circumstances." Tags are applied through Techniques, which may be bought (through Improvement Points) or done on the fly. The advantage of buying Techniques made up of specific combinations of Tags is that an improvised technique's cost must equal zero. Techniques can be applied to any check, unless they are limited in some way by a tag applied such as "only works with social skills" or "only works when facing ______". Think of Techniques as "Lenses" to focus Talents and Spells through. Methods of performing said Talents and Spells.

Spells and Talents feed off of a specific skill (Spellcraft in the case of Spells, a single specified skill in the case of Talents) and basically give you things to spend successes and marks on, known as "effects". So a fireball spell might give you the ability to spend successes on damage and area, with marks going to the duration of a fire created by it. Talents and spells are constructed of multiple effects in a similar way to how powers are handled in M&M. Talents and Spells are balanced by the fact that Talents are slightly cheaper, but a different effect requires a different skill.

Ok, I think I understand how the margin of success works.  It determines a figurative length and width of your technique.  My only criticism is that the width is always equally proportionate to the length, or vice-versa - unless if I have incorrectly interpreted your explanation.  If you could make it so that you could have a subtle effect stretched out for long periods of time or an effect that was short but intense, that would be impressive.  Not to mention it would allow for a very elegant, one-roll manner of modeling variability (could be applied to something like targeting different body areas, for example).

Keep this thread updated.  I'd really like to see how the system fleshes itself out.

You've correctly interpreted the margin of success rules, and I think I've come up with a couple of potential options for allowing for weak effects with a long duration and vice versa. Please give me your opinion on these various options, so I can try to figure out which one I'll go with:

1. Utilize the technique system to allow characters to declare that they are sacrificing successes for marks or vice versa. The problem with this option is figuring out what the value of a success versus a mark is. An example of this would be:

Faedamius wants to cast a spell to ward his tower from a rival Willful. He casts the spell, but before he rolls for it's effect, he improvises a technique that will decrease the successes by 2 but will increase the marks by 6 (or whatever equivalency there will be). This technique can be improvised because it has a total point cost of 0.

2. Simply allow characters to convert marks to successes and vice versa after they roll, to fine-tune the effect of an action. The problem with this would be specific instances where one is more important than the other (such as with a spell with a minor secondary effect). This is the option that I used in the example I gave you. It might seem to cause logical problems with certain rolls (like how do you have a lethal attack that deals 13 points of damage, but that only lasts for 1 hour?) but I feel that that could be worked around (for example, explaining such an attack as a very painful, but non-lifethreatening gash that very nearly puts someone out of commission and makes it easier for another to slay them while they're suffering from it, but that will no longer bother the target after an hour or so of rest).

I'd love to hear your opinion on these two options, as well as any ideas you might have.

Perhaps the attack kills you in an hour; you bleed out, or your lung collapses or something.

Another question, and then I'll get to my analysis: are "marks" always related to the duration of an effect?

Marks are typically related to duration, but also govern secondary effects of the the check (if any). So for example, if a character disarms an opponent of his or her weapon, the number of marks might determine how far the weapon is knocked away, rather than duration. If there are multiple secondary effects, marks are "spent" on them seperately. So if you have 5 marks and the effect has duration and a secondary effect, you might choose to spend 2 on duration and 3 on the secondary effect.

While your idea has merit, I want to keep things simple, and making it so that high marks are always good fufills that design goal. Like I was saying, perhaps a high damage, low duration wound is something that's relatively minor, but incredibly painful. It causes considerable impairment (in the form of wound penalties), and because of the pain that it causes, it's likely that any future attack against the opponent would be far more effective (meaning that they're easier to knock out or kill) but in an hour or two they'll be alright. Because while it might hurt like a bitch, and severely impact your chances of surviving a fight a superficial but painful wound is likely to stop bothering you in an hour or so (if it doesn't get infected).

I'm always looking for feedback, whether negative or positive. Please tell me what you think and I'll gladly help anyone who gives me feedback with their own work.

So a great length, small width attack could be a punishing, but ultimately sub-lethal blow?  I see promise in this. 

Just to make an example of ways you could manipulate this concept:
Armor could have a simple mechanic attached to it: it reduces width.  To illustrate, let's say you made a downward cut on your opponent's head with your two-hander for 13 damage and 6 width.  The armet he wears, being made of strong steel, reduces the width by 4.  A jarring concussive force passes through the helmet, dazing him hard enough to completely open his guard.  If you want to make it more granular, armor that is designed to deflect oncoming force could reduce length as well, as it is more difficult to land squarely.

However, I have personal qualms against the player directly manipulating the results.  In my opinion, it detracts from immersion. 

I hadn't considered the possibility of treating armor as a means of reducing successes and marks (aka length and width). That's actually more integrated with the system than the idea that I had been going with, a sort of "toughness save" akin to that used in mutants and masterminds, where the TN would be the number of successes+10. This solution would be simple and elegant, and would cut down on subsystems while preserving an evocative representation of events (which is really what I prize more than exhaustive detail). Thank you so much! This also parallels the approach I've taken with weapons, which essentially add successes to a successful Melee Weapon or Ranged Weapon check-adding marks to the equation just makes things far more interesting (and it makes sense that say an attack from a barbed dagger would take longer to recover from than an attack from a smooth-bladed longsword that did the same amount of damage in game terms).

This even works out well with how I was planning on handling mental defenses for things like sanity-rending spells, mental torture, etc. Using your idea, a character's Presence statistic could be used as armor for determining how marks and successes are reduced.

As for players determining the results of their opponent's failures, and converting marks to successes and vice versa I understand where you're coming from with your statement that it reduces player immersion. My perspective on the matter was that in a game where the players play individuals chosen by Destiny, and in which all of the players have the ability to reshape the world to suit their whims to some degree that a little player control over things like "did I inflict a painful wound or a deep one?" and "Did the thief drop his weapon, stumble and trip, or drop his guard?" is entirely appropriate. I think of it as sort of a subconscious extension of the Willful's innate ability to shape reality. That being said, what I think I'll do is making modifying successes/marks the province of techniques, equipment, talents and spells to give those elements more definition and to essentially leave it up to the group as to whether the GM or the players are responsible for "buying" the results of an opponent's failed roll. In any case, I'd definitely recommend that the GM gets to choose what failure results to "buy" from a player's failures. They shouldn't have a free ride in that regard, no matter their character's fate-changing abilities.

I've also done some math and determined that the idea of giving players the option of "buying" techniques whose point costs do not equal 0 is unbalanced at best. From now on, techniques will always be executable "on the fly" but the value of the tags applied must equal 0. Which means that characters can't just buy a technique that adds 5 successes with their improvement points and go crazy with that. It also introduces a give and take element to the game that I like the feel of, an example of this could be "I could go for an underhanded, nasty, personal attack in this debate. It'll be effective, but if I don't deliver it perfectly it'll ruin me and attract the wrong sort of attention." (IE. Choosing to use a technique which increases effectiveness with the Effective tag twice while adding the Risky and Attracts Attention Tags once each).

Now here's an example of a single attack carried out using my revised system:

Situation: Two knights in the final round of a tournament in honor of the lord of the realm. They are on foot, wielding Longswords (Effectiveness 3, Ease +1, Duration Increment +2 Piercing or Slashing), Kite Shields (Ease +3 to Dodge Defense), and a suit of full chain (Reduce Effectiveness 3 (Slashing) 2 (Bludgeoning), 1 (Piercing), Reduce Marks 5 (Slashing) 4 (Bludgeoning) 3 (Piercing), Ease Penalty (Defense) -1). Each has a Melee Weaponry skill modifier of +7 (+3 Str, +3 Skill, +1 Weapon) and a Defense of 18 (+3 Agility, +3 Perceptiveness, +3 Kite Shield, -1 chain penalty).

The first knight closes the distance and improvises a technique to increase effectiveness by 2 and ease by 2, but that applies a -4 ease penalty to Defense until the start of his next turn. He rolls a total of 21, earning a grand total of 6 successes and 3 marks (his opponent opted to take 10 on defense). The opposing knight takes 5 points of Lethal damage, but it will only last for 1 day (1 hour +2 steps= 1 day per mark). The Black Knight has 9 points on his first wound level, and his injury threshold is 4, so he suffers two injuries for the duration of the damage. The GM picks "Bleeding" and "Weak". The Black Knight will suffer 1 point of lethal damage every minute until he tends to himself, and takes a -1 ease penalty to attack checks in addition to the minus -1 wound penalty.

The Green Knight raises his sword high to salute the king before letting out a savage battle cry and charging towards the Black Knight, hacking at his foe with abandon and leaving himself open to counterattack. It's a savage thrust to the shoulder, but the Black knight jerks back at the last moment, leaving the Green Knight's Sword to shear through metal links and buff coat but leaves only a slowly bleeding wound where he intended there to be entrails.

The Black Knight, more cerebral than his opponent, will use both a Technique and a Talent. His talent is "Fight On", requiring a Conditioning skill check that has the following possible success effects:
Temporary Healing
Negate Injury
Bonus to Intimidate

and the following mark effect:
Duration

The technique that he'll apply to the roll will apply Increased Marks twice and Risky twice as well. He's trying his hardest to keep up his stamina for as long as possible, but he might end up pushing himself too hard. His conditioning bonus is +8 (4 Skill 4 Stamina). The roll TN is equal to the damage possessed +10 or 16. He gets a total of 25, easily making it and ending up with 11 marks and 4 successes. He applies 2 to negate injury, 1 to temporary healing and one to intimidate bonus. He'll gain these benefits for 11 minutes. Since that was a minor action, he still has a major and a moderate left. Which he uses to attack the Green knight using a Technique to add 3 points of Ease to his check, but that will almost certainly attract attention (Attracts Attention x3). What neither his opponent nor his lord knows is that the Black Knight is in thrall to a duke of the netherworld, a creature whose grasp he escaped, but who is keeping an eye on him. Any overly impressive feats are likely to draw his eye, and applying the tag three times means the servants that come after the Black Knight are likely to be dangerous. He rolls a total of 24, getting 5 successes and 1 mark. The wound's impairment will last for 2 days, and the Green Knight suffers two injuries "Limp" (half speed) and "Off Balance" (-1 to defense) (his injury threshold is only three) and a wound penalty of -1 to all checks. 

The Black Knight soldiers on with incredible endurance, not even acknowledging his foes attack as he goes for a stab to the gut. The Green Knight manages to deflect the blow somewhat with his shield, but this merely causes the blow to hit his leg, maiming him and throwing him off balance.

The Green Knight uses his Major action to attempt a "shake it off" roll, spending one of his Willpower points to do so before one of the intervals of the wound's duration has elapsed. This is a Willpower+Stamina check, with a DC equal to the effectiveness +10. His bonus for this check is +5 (+3 Stamina, +3 Will -1 Wound). He gets an 18 one success, reducing the marks on the wound by 1. He then uses a Talent called "Rapid Attack" to use a Moderate, rather than a Major Action to attack the Black Knight and perhaps get him to give some ground. Rapid Attack gives a -1 penalty to effectiveness, but decreases the action cost by 1 step (in this case Major to Moderate). He lashes out and gets a total of 14, a miss, with two stages of failure and 4 marks against him. The GM chooses to spend those two failures on the Green Knight dropping his weapon, and the marks to the distance it flies. It flies 4 feet away. 

The Green Knight summons reserves of willpower and strength to attempt to act as if the wound is not there, and by this act of Will, actually cause the wound to disappear. While the seriousness of the wound alleviates somewhat, it doesn't abate. Getting desperate, he strikes low and quickly with a hasty attack. But the Black Knight is too quick, and backs away as the Green Knight over extends himself and then knocks the sword from his opponent's hand with his shield. "Do you yield?" he asks menacingly, pointing his sword towards the Green Knight's throat.

The black knight rolls an intimidate check with his major action, using a Technique to grant it the "Supportive (Limited to Persuasion, One Check) x2 " and "Difficult -1" tags. He'll take a -1 penalty to his roll (canceled out by the bonus granted by his earlier talent. But if he succeeds, he gains a +2 bonus on his next Persuasion roll against the Green Knight. He'll need all the help he can get to fight off the demonic assassins he knows are coming his way. His bonus is +8 (Intimidate 4, Presence 4) vs. the Green Knights Mental Defense (Intelligence+Perceptiveness) or 10 (The green knight isn't the sharpest tool in the shed, Perception 3, Intelligence -1, and -2 for his wound penalty and the "off balance" injury ). The Green Knight elects to roll, getting a 6. The black knight gets a 19 for a total of 6 successes and 13 marks. The Black knight is utterly cowed for at least 13 minutes.

"Of course, I cede the field to umm....a warrior far more skilled than I." The Green Knight mumbles. The Black knight comes closer, shaking the Green Knight's hand and basking in the roar of the crowd. "Good...because I have a favor to ask of you, sir knight."

*Cue Ominous Music*

there's a lot of discussion here and my point is small and simple...

it seems that with a threshold of 2 to gain marks that, unless the rolling scheme is very standard, marks will be given in practically every roll which can bog things down.  It might be hard for the average player to keep up and try to figure out what to do with the marks all the time.  You have nice cinematic examples but the story is almost completely dice driven, meaning that for you to progress the story you need to not just succeed, but to do more than needed.  This could encourage players to stack certain skill so they can ensure they always get marks.  I think players might exploit the mark system constantly taking the best ones... (trip, disarm, daze...)  Be careful with the math it looks like scores can get into the 30's+ which means a lot of stat adding, attribute + skill + marks + bonus + 2d10.

My system uses a similar mechanic but you have to get a critical success to do so which means doubling the opponent's score which only happens with very bad luck or lopsided match ups.  Critical hits happen the same way in combat.

Whats nice is with a typical initiative order system this could encourage teamwork.  I knock the guy down, next player pounces on him, third player stabs him while down.

A suggestion is to break the rolling down into minor and major marks.  You need x to get a minor and 2x to get a major.  This would make getting marks special.  Also a strange cool mechanic could be to let the next PC who is going spend the mark because if they go next they would get the advantage from a  teamwork standpoint.  Place the marks on a sheet so players know their options or roll randomly, or let the GM decide.  This would be cool as the player describes the attack and his goal and if a mark or negative mark is received then the GM can add the cinematic element based on his best judgment.

Thank you for your feedback Locke. Just to clarify, Marks don't add to the roll of the die, they're determined from how high of a result you roll, and then spent on duration and secondary effects (less significant stuff related to a power, like the amount of light cast by a spell to conjure fire). Marks also aren't used to contribute to the "big ticket" effects, like Disarming someone or Dazing them-that's a function of successes. Marks are simply the amount by which your roll exceeded (or came up short of) the TN.

So for example if you get a combined roll of 20 vs. TN 10. You have 10 marks (because you exceeded the TN by 10) and 5 successes (since you get one success for every 2 points you exceed the TN by).  You can spend the 5 successes on the major effects of whatever skill, talent, spell etc that you are using, while the marks get used for minor stuff and for duration. Does that clear some things up for you?