Several people have said that splash weapons and fireballs DO NOT USE THE SAME MECHANICS. It is a very bad comparison.
to a large creature a fireball does between 5d6 to 10d6 fire damage, an flask of alchemist fire does (using my method) 1d6+3 fire damage plus a second round of (dc:15) 1d6 fire damage.
Lets compair the two, Fireballs and Alchemist fire flask:
Fireball damage: 5d6 to 10d6 averages to 17.5 (for 5d6) to 35 (for 10d6) save DC: 14 minimum.
Alchemist fire flask damage: 1d6+3 averages to 6.5 plus save DC:15 for 3.5 more.
Fireball is a spell, that cost you no gp to cast (beyond a spell component pouch).
Alchemist fire is a alchemical item that cost you 20gp per use.
Fireball effects a 20ft spread that requires no attack roll, everyone can take full damage.
Alchemist fire is a touch attack item with a range increment of 10 feet and 5ft splash area from the point of impact, only the person hit takes full damage.
The only thing that they share is that they both do fire damage.
How is allowing alchemist fire to do 3 extra points of damage when hitting a large creature when the fireball is doing AT LEAST 11 points of damage more??
Its only when you consider the Alchemist class ability to add INT to splash damage might you consider it breaking the system. So I suggested to limit the bonus damage to one square of splash damage to keep from making it broken.
