[4e]Anything unbalancing about this weapon?

[NeoVid]

When making my latest character, I realized that the perfect weapon for him would be 1)a hammer, 2)have reach... and there aren't any of those. The GM said he'd be willing to homebrew one, and it seems like it would be no different than any other polearm. d10 damage, reach, polearm/hammer. That there isn't one already seems more like an oversight than it being purposely left out of the game for whatever reason.

Also, I can't remember the names I was told for the RL polearm hammers...

[Kurald Galain]

No, that doesn't strike me as unbalancing.

The primary thing hammers have going for them is Hammer Rhythm, and that combos best with dual wielding.

[Gralamin]

When making my latest character, I realized that the perfect weapon for him would be 1)a hammer, 2)have reach... and there aren't any of those. The GM said he'd be willing to homebrew one, and it seems like it would be no different than any other polearm. d10 damage, reach, polearm/hammer. That there isn't one already seems more like an oversight than it being purposely left out of the game for whatever reason.

Also, I can't remember the names I was told for the RL polearm hammers...

Bec de Corbin is probably the name you are looking for.

Mechanically, I'd make it:
Superior Melee Weapon
{table=head]Weapon|Prof|Damage|Range|Price|Weight|Group|Properties
Bec de Corbin|+2|d10|-|25 gp|12 lb.|Polearm, Hammer|Reach, Brutal 1[/table]

[pasko77]

Also, I can't remember the names I was told for the RL polearm hammers...

Maybe the name you're searching for is "maul".

[Shardan]

The old standard was 'Lucern hammer'
1d8 hammer,reach should be fine as a martial weapon.

Bec de Corbin should be Polearm, reach, (if I were DM I'd say you could use it as Hammer 1d10 or as pick 1d8 brutal 2 choose before the attack) but at the very least it should have hammer and pick since its main purpose was to have the two heads (like many polearms have two head types in one)

[Colmarr]

Also, I can't remember the names I was told for the RL polearm hammers...

Lucern hammer or Bec-de-Corbin, although the latter is more of a true "hammer" than the former.