Possible to attack enemy on ceiling with sword where ceiling only 10 feet high?

[Voomer]

If an enemy is at the level of a 10 foot ceiling, could a tall barbarian with a sword attack it normally, since the barbarian could easily poke the sword 10 feet into the air? What penalties would apply in this situation?

[Are]

If the ceiling is 10 ft above the floor, that means you have two vertical 5-ft squares. Someone on the lower square would easily reach someone on the upper square to attack, with no penalties.

[FallofCamelot]

In short, yes.

For simplicity's sake each square is a three dimensional 5ft cube so you can attack the flying NPC above you because he's only 5ft away.

The flying NPC gets +1 to attack the barbarian as he's attacking from the higher ground.

[Aldarionn]

Are has it right. The two creatures are adjacent and thus able to attack one another.

[Voomer]

Makes sense. Thanks folks.