In Fenths Press, it says sacrificing a creature costs 20 Action Points, but I can sacrifice them even when I have no AP?

that is probably due to the fact that the regen counter has already run through the 10 minutes and given you the 25 but it hasnt registered yet on your action points list

it takes about a minute or so to register as do the vitality points

give it some time and you will see does it let you sacrifice more than one or can you only do one at a time then

I tried it today. I went there with four creatures and sacrificed them all with 50 action points. All of my action points gone but I managed to make a 80 action points work with 50 action points.

i dont know why it let you but you should contact mur about this as iwill be doing so aswell

thank you for pointing this out

This has always been true... it doesn't seem like a problem as if you have 0 AP there isn't anything you can do that'll abuse s your ability to sac multiple things at once (you'll have extra VE and VP, but no way to use them).