toxicspirit
First Post
A club! 

Yes, that was what I was arguing for, that a rogue bugbear with a broadsword and dagger can apply his rogue powers with the dagger. Your original post implied that he can't.
I have no idea where the whole broadsword for rogue powers just because you have a dagger in your offhand interpretation came from.
A Ranger's Two-Weapon Fighting Style and the Off-Hand property of weapons are examples of exceptions that prove the rule. By telling you explicitly what you can do, they also make it abundantly clear what you can't do.
Reasonable people understand this, especially in an exception-based system.
But .. doesn't the off-hand weapon property describe exactly that?
It seems pretty straightforward to me:
General Rule: PHB pg 270
Simply wielding a weapon in each hand doesn't allow you to make two attacks in a round. If you hold two melee weapons, you can use either one to make a melee attack.
Off Hand Property: PHB 217
An off-hand weapon is light enough that you can hold it and attack effectively with it while holding a weapon in your main hand. You can't attack with both weapons in the same turn, unless you have a power that lets you do so, but you can attack with either weapon. (Read with the general rule above, that you can only make an off hand attack if the off hand weapon has the off hand property.)
Ranger Two-Blade Fighting Style: PHB 104
Because of your focus on two-weapon melee attacks, you can wield a one-handed weapon in your off hand as if it were an off-hand weapon. (Read with both the rules above that you can use any one-hand weapon in the off hand.)
1. Anyone can have weapons in both hands.
2. Anyone can effectively use a weapon in the off hand if it has the off-hand property. (The converse being that you can't wield/use one if it doesn't have the off-hand property, ie. you can hold a non off hand weapon in the off hand you just can't use it.)
3. A TWF ranger gains the off-hand property on all one handed melee weapons held in the off hand.
What is so hard to understand?