do double rolls stack

[Flipguarder]

I'm sure this has been answered somewhere, so I apologize for asking again... but.

Do multiple features from different sources that grant you multiple rolls stack?

Specifically I'm looking at Tenacious Weapon and Vicious Action

Tenacious Weapon

Power (Encounter): Free Action. Use this power before you
make an attack roll with this weapon. Roll twice and take
the better of the two results.

Vicious action

When you spend
an action point to make an attack and that attack
misses, you can reroll that attack roll but must use the
second result.

After carefully reading these, I would have a hard time beliving they don't stack. So lets bring out another example. Tenacious weapon and Oath of Emnity

Effect: When you make a melee attack against the target
and the target is the only enemy adjacent to you, you
make two attack rolls and use either result.

 

[corncob]

Here's the rest of the Oath of Emnity text:
If another effect lets you roll twice and use the higher result when making an attack roll, this power has no effect on that attack.

If an effect forces you to roll twice and use the lower result when making an attack roll, this power has no effect on that attack either.

If an effect lets you reroll an attack roll and you rolled twice because of this power, you reroll both dice.

 

[Flipguarder]

lol... well that makes that a terrible example...

 

[DracoSuave]

1) This is one of those 'DM decides' moments. Probably cause it comes up so rarely. That said, I'm chipping in 2 cents anyways.

2) Rolling two dice and choosing the higher is a one-time deal. You do it, it's done. If you use a reroll based upon the result of that, you don't get to do it again, cause you've already done it.

3) Oath of Emnity specifically says that you -do- reroll both dice when you get to reroll, so it's a specific exception and that neither supports nor opposes point 2) beacuse rerolls with Oath of Emnity are -not- corner cases that come up rarely, if only because of Elf Avenger.