Did I rule this right?

[Railak]

So, one of my players is playing a warder and is using the stance Vigilant Keeper's Stance of the Eternal guardian discipline. He's using a chain reach weapon as well.
The stance makes it so any squares he threatens are treated as difficult terrain for enemies.
So his character got blinded, I don't remember if it was from an attack or a fumble, but it was a short term blinded effect. He entered into his defensive focus since he didn't want to deal with the 50% miss chance. This increased his threatened area by a bit more.
Now we ran with the assumption that even though he couldn't see his threatened area was still treated as difficult terrain.
I'm pretty sure I ruled it right because blind didn't say anything about threatened area.. but I just wanted to check with the great people of Giants to see if any of you know of any actual rules that contradict this.

[Nizaris]

Being blind does not remove your threatened area as that is defined by all squares you can make melee attacks to. The player can't make AO's but that wouldn't interfere with the difficult terrain if it doesn't require the player to have the ability to make AOs against creatures passing through it.

[RNightstalker]

He can't threaten what he can't see unless he has a form of Blindsight.

[Blackhawk748]

He can't threaten what he can't see unless he has a form of Blindsight.

Got a citation for that?

[RNightstalker]

Got a citation for that?

Just reading the glossary for blinded and blindsight.

[Nizaris]

Page 180 of Core Rule book "Threatened Squares: You threaten all squares into which you can make a melee attack, even when it is not your turn."

Even though you're blind, if you're able to make melee attacks to the square, you threaten it by RAW.

[Crake]

Page 152 of the players handbook, last paragraph of total concealment: "You can’t execute an attack of opportunity against an opponent with total concealment, even if you know what square or squares the opponent occupies"

Blind states: "All opponents are considered to have total concealment (50% miss chance) relative to the blinded character."

Thus, you cannot make attacks of opportunity while blinded.

Side note: Blind-fight does not mention changing this rule at all, so even with blind-fight, you cannot take attacks of opportunity while blind.

[icefractal]

That's separate from threatening squares though. You still threaten a square (ex: for flanking) after you've used your aoo(s) for the round.

So I'd say yes - correct ruling.

[Doctor Awkward]

Yes.

You threaten all squares into which you can make a melee attack. Being blinded does not change this, in fact while blind you are expressly and specifically allowed to still make melee attacks into squares.

If you have an ability to treat all squares you threaten as difficult terrain, you retain the ability to do so regardless of conditions you are suffering unless either the ability or one of those conditions says otherwise.