I've been working on a replica of the halo shielding system, and I finally got it to work. It works in both single player and multiplayer. The wad itself is just a simple room with a switch that damages you so you can test the shielding effects. (Sorry, I'm a god awful mapper and couldnt really come up with much for monsters) Please post your feedback on this concept. The more the merrier.
Also: I'm beginning to work on the concepts twoard useable vehicles in doom, more on that later
EDIT: This mod is DONE, and has been done for a long ass time. I was just too lazy to update this thread.