[quote=@Sionnie]
<Snipped quote by VKAllen>

I can not advocate this system but i'll go with it... every game has it's rules no matter how silly What if i use a long sword and a dagger.. then i get slashing damage and if i use it it could be piercing damage as well(if that is allowed)
[/quote]

The difference between a longsword and a rapier is that the two weapons uses two different stats. Longsword uses Strength as its determining Stat and Rapiers uses Dexterity as its determining Stat.

However, I will give you the interchangeability of the weapons being slashing or piercing. Technically all swords are capable of doing it.