Yes - By Interpretation

The answer is right there in the explanation of Might Defense on p.30 of the Numenera core book - emphasis mine:

Might defense: Used for resisting poison, disease, and anything else that can be overcome with strength and health

Are you going to block a poison dart or dodge a stunning ray with Might? No. It doesn't make any sense.

Can you block a giant sword with it? Maybe. Is the threat of the sword defined by its speed or its size and power? In my game, intercepting a giant sword isn't going to be the problem - it'll be stopping it.

So by RAW as well as the spirit with which the game is written, two factors will impact whether using Might defense is correct:

1. How is the threat described? Is it a fast threat? A powerful one?
2. How are you describing your response? "I defend with Might!" Isn't a response. "I grab the blade of the axe with my cybernetic hand and tear it out of his grasp!" is a response. And a Might defense. "I duck beneath the blow!" Is another response - and a Speed defense.

In his series of recent blog posts, Monte seems to support the idea that what makes sense in the game fiction is a powerful influence and that the GM is empowered to make decisions that make sense in the context:

The Cypher System is designed to put the power in the hands of GM and the players (probably in that order). The rules exist to help, not dictate. That doesn’t just mean that the rules are meant to be ignored, however. That means that the rules were designed to make way for GM logic. There aren’t a lot of fiddly rules or things that require rulebook lookups.

Yes - By Interpretation and by RAW

The answer is right there in the explanation of Might Defense on p.30 of the Numenera core book - emphasis mine:

Might defense: Used for resisting poison, disease, and anything else that can be overcome with strength and health

Are you going to block a poison dart or dodge a stunning ray with Might? No. It doesn't make any sense.

Can you block a giant sword with it? Maybe. Is the threat of the sword defined by its speed or its size and power? In my game, intercepting a giant sword isn't going to be the problem - it'll be stopping it.

So by RAW as well as the spirit with which the game is written, two factors will impact whether using Might defense is correct:

1. How is the threat described? Is it a fast threat? A powerful one?
2. How are you describing your response? "I defend with Might!" Isn't a response. "I grab the blade of the axe with my cybernetic hand and tear it out of his grasp!" is a response. And a Might defense. "I duck beneath the blow!" Is another response - and a Speed defense.

In his series of recent blog posts, Monte seems to support the idea that what makes sense in the game fiction is a powerful influence and that the GM is empowered to make decisions that make sense in the context:

The Cypher System is designed to put the power in the hands of GM and the players (probably in that order). The rules exist to help, not dictate. That doesn’t just mean that the rules are meant to be ignored, however. That means that the rules were designed to make way for GM logic. There aren’t a lot of fiddly rules or things that require rulebook lookups.

Furthermore, on p. 382 of the Cypher System Rulebook, it states:

...you could allow a PC to use a different stat for a task. For example, a character might try to break down a door by examining it closely for flaws and thus use Intellect rather than Might. This kind of change is a good thing because it encourages player creativity.

This is not the kind of game that uses the rules to enforce the story, it's the kind of game that uses the fiction to govern the use of the rules.

Yes - by RAW

The answer is right there in the explanation of Might Defense on p.30 of the Numenera core book - emphasis mine:

Might defense: Used for resisting poison, disease, and anything else that can be overcome with strength and health

Are you going to block a poison dart or dodge a stunning ray with Might? No. It doesn't make any sense.

Can you block a giant sword with it? Maybe. Is the threat of the sword defined by its speed or its size and power? In my game, intercepting a giant sword isn't going to be the problem - it'll be stopping it.

So by RAW as well as the spirit with which the game is written, two factors will impact whether using Might defense is correct:

1. How is the threat described? Is it a fast threat? A powerful one?
2. How are you describing your response? "I defend with Might!" Isn't a response. "I grab the blade of the axe with my cybernetic hand and tear it out of his grasp!" is a response. And a Might defense. "I duck beneath the blow!" Is another response - and a Speed defense.

Yes - By Interpretation

The answer is right there in the explanation of Might Defense on p.30 of the Numenera core book - emphasis mine:

Might defense: Used for resisting poison, disease, and anything else that can be overcome with strength and health

Are you going to block a poison dart or dodge a stunning ray with Might? No. It doesn't make any sense.

Can you block a giant sword with it? Maybe. Is the threat of the sword defined by its speed or its size and power? In my game, intercepting a giant sword isn't going to be the problem - it'll be stopping it.

So by RAW as well as the spirit with which the game is written, two factors will impact whether using Might defense is correct:

1. How is the threat described? Is it a fast threat? A powerful one?
2. How are you describing your response? "I defend with Might!" Isn't a response. "I grab the blade of the axe with my cybernetic hand and tear it out of his grasp!" is a response. And a Might defense. "I duck beneath the blow!" Is another response - and a Speed defense.

In his series of recent blog posts, Monte seems to support the idea that what makes sense in the game fiction is a powerful influence and that the GM is empowered to make decisions that make sense in the context:

The Cypher System is designed to put the power in the hands of GM and the players (probably in that order). The rules exist to help, not dictate. That doesn’t just mean that the rules are meant to be ignored, however. That means that the rules were designed to make way for GM logic. There aren’t a lot of fiddly rules or things that require rulebook lookups.

Yes - by RAW

The answer is right there in the explanation of Might Defense on p.30 of the Numenera core book - emphasis mine:

Might defense: Used for resisting poison, disease, and anything else that can be overcome with strength and health

Are you going to block a poison dart or dodge a stunning ray with Might? No. It doesn't make any sense.

Can you block a giant sword with it? Maybe. Is the threat of the sword defined by its speed or its size and power? In my game, blocking a giant sword isn't going to be the problem - it'll be stopping it.

Go ahead and put your shield up quickly - the oncoming truck doesn't care

So by RAW as well as the spirit with which the game is written, two factors will impact whether using Might defense is correct:

1. How is the threat described? Is it a fast threat? A powerful one?
2. How are you describing your response? "I defend with Might!" Isn't a response. "I grab the blade of the axe with my cybernetic hand and tear it out of his grasp!" is a response. And a Might defense. "I duck beneath the blow!" Is another response - and a Speed defense.

Yes - by RAW

The answer is right there in the explanation of Might Defense on p.30 of the Numenera core book - emphasis mine:

Might defense: Used for resisting poison, disease, and anything else that can be overcome with strength and health

Are you going to block a poison dart or dodge a stunning ray with Might? No. It doesn't make any sense.

Can you block a giant sword with it? Maybe. Is the threat of the sword defined by its speed or its size and power? In my game, intercepting a giant sword isn't going to be the problem - it'll be stopping it.

So by RAW as well as the spirit with which the game is written, two factors will impact whether using Might defense is correct:

1. How is the threat described? Is it a fast threat? A powerful one?
2. How are you describing your response? "I defend with Might!" Isn't a response. "I grab the blade of the axe with my cybernetic hand and tear it out of his grasp!" is a response. And a Might defense. "I duck beneath the blow!" Is another response - and a Speed defense.