Types of Gods

There are gods and then there are GODS. - The Shadow Tyrant

The Classifications of God are as follows:
Elder Gods: Native to the Far Realm and impossibly powerful within their realm they outstrip the power of anything within the Mortal Realm. They are very few in number and generally their ability to influence the Material Plane and those on it is very diminished and they require many followers to manifest their power upon the Planar Realms. They are very powerful within the Astral Sea however.
True Gods: The Most powerful form of the Planar Gods, these are Gods who have the ability to warp the Planar Realm and can empower their followers to the greatest of heights. The Mortal Gods of the Old World were originally True Gods but at some point were lowered into Proto Gods to be able to protect their followers in the Purge War. True Gods cannot be killed in the same sense as a Proto God, not without destroying all of their followers, but they cannot manifest in Physical Form without a large group or signifigantly powerful follower present and even then for only moments. Living True Gods include: Sarissa, Asmodeus, The Shadow Tyrant, Malgeron (though he resists the true ascension as he could no longer fight upon the Material Plane in the event he was freed from his bonds) and Garn Zoren.
Proto Gods: These can be signifigantly powerful Mortals or "Ascended" from mortality by powerful magics, such as the Divine Spring. Proto Gods are powerful entities and capable of using their power unrestricted in the material realm, as evidenced by the Purge War. They can be slain by Mortals and mundane weapons though to do so requires extreme damage to their form. When a Proto God is killed their essence can be transferred to another being, allowing them to ascend or to empower another Proto God. These include most of the Gods created by the Divine Spring.

Demigods: Demigods are signifigantly powerful mortals who are on the path to becoming a Protogod, though they have already pushed past normal Mortal Limits. To become a Demigod one must have something push them past Mortal Limits, a powerful entity dying in their presence or a blessing from a God. Demigods include the likes of Emperor Autrion, High Lord Lukrag, Duke Vinalmo Efrezi or Great Wyrms. This also includes the Offspring of all types of God.
To Ascend up the chain one must either kill a more powerful entity or have some powerful magic or force push them beyond their limits.