Is it possible to turn spells into spell-like/supernatural abilities? A single spell or all of your spellcasting.
\$\begingroup\$ Is the question asking whether it is possible to turn a spell into an SLA or Su, or is the question asking whether it is possible to turn all your spellcasting in total to SLA or Su? \$\endgroup\$– KRyanFeb 26, 2016 at 3:04
\$\begingroup\$ Good question, Both is nice ^^ \$\endgroup\$– SimonFeb 26, 2016 at 3:07
Turning a single spell, or limited number of spells, into a spell-like ability or supernatural ability is definitely possible.
For spell-like ability, the most immediate example is the archmage, which has an option for its high arcana class feature simply called “Spell-like Ability.” You choose a spell, permanently lose one 5th-level spell per day as well as one spell per day of the chosen spell’s level, and you get to use that spell 2/day as a spell-like ability. This results in basically trading a 5th-level spell slot for a higher level spell slot, but you lose the flexibility of having possibly prepared something else in those slots.
There are other ways to get spell-like ability versions of selected spells; too many to list here.
Supernatural spells are rarer. The only example to come to mind is the dweomerkeeper prestige class from the web enhancement to Complete Divine. This is generally considered an overpowered class because of its ability to turn any spell into a supernatural ability, since supernatural abilities have significant advantages over spells. In particular, unlike the archmage, dweomerkeeper neglects to say you still have to pay material and XP components on the chosen spell, which means you can use, for example, wish as a supernatural ability that doesn’t require XP.
There is no way to turn all of a chosen class’s spellcasting to spell-like or supernatural. However, one particular class does this naturally: the shadowcaster from Tome of Magic. There are a lot of things going on with the shadowcaster, which I’ll skip, but the long and short of it is that the shadowcaster uses “mysteries,” which start out as arcane spells. When the shadowcaster gets 4th-level mysteries, his 3rd-level and lower mysteries start to count as spell-like abilities (his new 4th-level mysteries are still cast as arcane spells). Then when he gets 7th-level mysteries, his 3rd-level and lower mysteries start to be used as supernatural abilities (and his 4th through 6th-level mysteries start to be spell-like, and his new 7th-level mysteries are still arcane).
1\$\begingroup\$ @DanB No, shadowcaster only gets effects up to 3rd-level as supernatural. The dweomerkeeper can get wish though. \$\endgroup\$– KRyanFeb 26, 2016 at 4:29
\$\begingroup\$ Animate dead spell-like? There are many ways to get a version of a selected one \$\endgroup\$– SimonFeb 27, 2016 at 20:35
3\$\begingroup\$ One minor nitpick: Phaerimm (Lost Empires of Faerun) have sorcerer casting as spell-like abilities with no components, with a level equal to their character level. Though this is a bit of a nuclear option, it is the one way of getting an entire class' casting as SLAs. \$\endgroup\$ Feb 28, 2016 at 1:13
Innate Spell from Compete Arcane is a feat that allows a player to convert a spell into a spell like ability. It can be used once per turn, at will. The drawback is that the player also permanently loses one spell slot 8 levels higher.
So, for example, if you wanted Magic Missile as a spell like ability, you would have to spend the feat, and permanently lose one 9th level spell slot. Then you could cast Magic Missile once per round without needing to worry about verbal or somatic components.