Does glowering threat work the same way as a mark or differently?

Question

I'm playing a high level fighter in a long term D&D campaign and a specific issue related to one of my powers has come up regularly and been a source of dispute at our table.

I have the power Glowering Threat. Which inflicts a -5 penalty to attack rolls. Here is the text from the power card:

Until the end of your next turn, each target takes a -5 penalty to attack rolls against any creature other than you.

The problem is that I see this as affecting all attack rolls where my character is not the target. But the DM want's to treat the penalty the same way that marks work.

It seems that an example may help clarify.

 xMC
 MBx
 MxA

• M: Monster
• B: Fighter
• C/A: Allies

The Example

• B uses an attack power that targets all 3 enemies.
• B uses glowering threat.

He now has 3 marked monsters in front of him who are all also taking the penalty from glowering threat as well as the mark.

Please address the following three scenarios in an answer with their appropriate penalties:

• Monster at the top of the screen attacks character C with a melee attack.
• Monster in the middle attacks character B (the fighter in this case), shifts, and attacks character A with the same attack power.
• Monster on the bottom uses a blast 3 power that targets all 3 characters.

Answer 1

The text seem to be self explanatory.

Except it's specifically noted that it works like the fighter mark, it's supposed to mean literally what it says and apply even when the attack includes you as a target (we can see the combat challenge feature description here).

I'll ellaborate each case:

• Monster at the top of the screen attacks character C with a melee attack.

It has the -5 penalty for Glowering Threat (the character is not you) plus -2 for the mark (attack doesn't include you as target), for a total of -7.

• Monster in the middle attacks character B (the fighter in this case), shifts, and attacks character A with the same attack power.

Over your character, it has no penalty (as we already knew).

Over character A, it has the -5 penalty for Glowering Threat (the character is not you), and if the secondary attack has a new target identifier (like "target: an enemy adjacent to the first target") plus -2 for the mark (attack doesn't include your fighter as a target), for a total of -7.

• Monster on the bottom uses a blast 3 power that targets all 3 characters.

Over your character, it has no penalty (as we already knew).

Over characters A and C, it has the -5 penalty for Glowering Threat (the characters are not you). The combat challenge penalty doesn't apply because yor fighter is included as a target ("target: every enemy in the blast").

Abiding to the rules, it should work like described.

Answer 2

To first answer the headline question, this works differently than a mark as it does not last until the end of the encounter or death of the creature, etc. Generally, Marks last until you die, the creature dies or are removed by some other instance, unlike the conditional of Glowering Threat which falls off after your next turn.

Nothing that I can find in the rules relating to marking targets says that the effect of marking does not stack with other similar penalties. Therefore, I would say that if your fighter has chosen to mark the creatures with their combat challenge, the -5 and -2 would combine for a -7.

Now to give my interpretation of the 3 scenarios described.

1. Monster is marked by you, attacks Ally 'C' and takes -7 penalty to that attack as it does not attack you.

2. The attack against you has no penalty, but after the shift he makes a new attack and would have the -7 to attack as long as the second attack clarifies there is a new target.

3. Your DM should apply a -5 penalty to the attack rolls against your 2 allies since they would be making an attack roll that targets you, thereby negating the mark but retaining the effects of Glowering Threat. The roll that specifically against you would function normally. Page 271 of the PHB states:

Multiple Attack Rolls but One Damage Roll: When you make an area attack, you make a separate attack roll against each target in the area of effect, but you make a single damage roll that affects all the targets. A Large or larger creature hit by an area attack is affected only once by the attack, even if multiple squares of the creature’s space are in the area of effect.