Holder for the agenda and act decks during Arkham Horror LCG play sessions.
The idea is that when you advance either deck, you take the top card, flip it, and put it in the upper holder.
Note: This one was made to fit unsleeved cards, but I have now made a version of this to accommodate sleeved cards too. So if you play with sleeved agenda and act decks, go print this one instead. STL files with or without doom tray, and split versions are available for that as well!
I separated it into a separate thing because the files are big, and the file list would get too cluttered otherwise.

You can print this with or without the so-called Doom Tray.
If you want to use it with my doom tokens from here, you can print the one with the Doom Tray, which has slots for those tokens.
If you are playing with the cardboard doom tokens from the game, I would recommend printing the one without the Doom Tray. Otherwise, I think they might be difficult to take out again (my doom tokens have the little tendrils to hold on to).

The Blender file contains the model as separate objects. If you want to modify it before exporting to a new STL file, you need to merge them into a single mesh with the Boolean union modifier before you export. The Doom Tray slots need to be made with the Boolean difference modifier.
There are two meshes for the base included, one with and one without the tray. You can switch them out in the object.

I have made a split version of both now as well, for people with smaller print beds. If your printer is not tall enough, Slic3r (and probably other software as well), should be able to make a horizontal cut pretty easily.

I have only printed this once, and discovered a few very minor things I wanted to change before publishing, so there are some slight differences from the holder in the photo. I re-merged it to fix a few overhangs created under the base of the tendrils and under a corner in the foundation. I also made the doom token slots a bit more shallow.

Added 9/2 - 2019: Separate Doom Tray for smaller printers.