Also, if you want an atlatl, you can buy a crossbow or bow and sub it. If your character has the strength and experience to use it to throw a spear, it would be in there wheelhouse to do that then - no need for any spells. 

Our Jenna was up this morning and I was asking her about. She always amazing at coming up with practical subs for thing!

Looking up what an atlatl is and how it works, I think the closest sub would be some flavour of bow or crossbow. Lots of the same principles, just with a light spear instead of an arrow.

I like to think I am pretty good at figuring out what subs for what, and there is almost always something to sub for the more obscure stuff. (Except a platypus, loathful creatures that they are.) As it says in the rules, if you're not sure what item to use to sub, you can ask, and we will suggest something. It's not possible for us to add every item suggested (some are really niche and it's not practical), but there is definitely something for people who want to RP the obscure. That part of the staff's job, to help with subs and stuff.