A Shemite mercenary attacks my Brythunian adventurer. He rolls and gets 2 Successes. The Brythunian elects to pay a Doom and Defend, adding another Doom to increase the d20s rolled to three. Unfortunately there are no successes on the Defend roll. So…

As the Shemite needed to roll more successes than the Brythunian and did so by 2… 2 momentum was generated by the attack for +2 Damage Dice

or

The defense failed so the attack was against the standard Difficulty 1 and thus created 1 momentum with 2 successes for +1 Damage Dice.

(This is assuming the GM wants to use the NPC Shemite’s momentum for damage and not added Doom.)

Ok, your right of course but thats not my question. Does the struggle actually increase the success of a roll by allowing a base 0 result measured against the opponent’s attack when a regular attack would have been against a minimum of Difficulty 1?

It’s possible for the attacker and defender to have different difficulties. That’s why whoever rolls the most momentum wins the struggle. The winner gets the difference between the momentums.

As others have said. Determine difficulty of the attack check for attacker and difficulty of defense reaction for defender, these can be different.

Ie Skeleton attacks an Aquilonian knight in a dark chamber.
Skeleton Attack Difficulty = 1
Aquillonian Knight Defend Difficulty = 2 due to darkness

Each rolls their skill check and compares to their difficulty and comes up with a momentum. (failing the skill check means you outright fail at the test and lose the struggle and essentially generate 0 momentum)

Momentum values are compared, the one with the highest is successful. The difference in those two momentum is the remaining momentum for the victor.

Ok, so then there is a risk to defending. By failing the attacker compares their successes to your 0 momentum instead of difficulty 1. Something to think about if your Parry sucks.

No. Each participant in the struggle compares their own successes to their own difficulty to determine whether or not they were successful. If one party is successful and the other is not, then it is essentially like a normal skill test.

You only compare Momentum if both parties succeed. Then the party with the most Momentum succeeds (number of successes and difficulty is irrelevant here). The successful party then keeps their Momentum minus the opponent’s Momentum.

That said, parrying is theoretically a risk because you can roll Complications!

But if a character rolls 1 Success during a struggle, that doesnt equate to momentum… momentum is earned when your roll MORE than you need to. In this case, typically, its against a Difficulty of 1, so 1 success generates no momentum for either participant. Even if one fails there is no momentum to count. So, what Im hearing is that if a Parry attempt fails, you just resort to a regular attack, v.s. whatever the Difficulty would have been otherwise. (usually a 1) in which case theres no risk in Parrying other than Complications as you say. 1 Success against a failed Parry is simply a success (assuming Difficulty 1), allowing damage to be inflicted.

From the rules, it is not 100% clear that during a struggle, the attacker’s Difficulty remains the same and that the defender’s Difficulty is 1. But this would make sense to me and that is how I always played it.

The difficulties of the attack and defend can be different based on many factors. The attackers difficulty can be higher if its a second action, if Create Obstacle is used, and so forth. The defend is also a base 1 difficulty but it could be higher based on different factors as well.

In the Struggle section of the book it says the attack difficulty and defend difficulty can be different. The attackers difficulty does not change just because its being opposed.

Yes the only risks to a parry is the a rolled complication and doom given to the GM.

@jujo The attacker would gain 1 momentum, not one more damage, or damage dice or anything. They can then choose to spend that extra momentum on 1 point of damage or 2 armor soak reduction, or any number of things. They get Momentum not damage dice from an attack roll that exceeds what is necessary (Typically D1).