[gurps] WoW: DR, "ablates" ER as well as DR?

[Syndaryl]

Another odd question in persuit of converting from World of Warcraft to
GURPS.

The power concept is a switchable force field. Activating the field
costs two points of Energy Reserve, and leaves it active for one
minute. This force field can stop 4 points of physical damage and then
it is spent, and you have to spend another two ER to reactivate it.
This shield canot be bypassed by armor reducing/dividing effects. So
far, so good: 4 DR with Force Field, Costs Fatigue 2, Ablative, Limited
(Physical attacks), Nuisance Effect: Cannot be maintained at half cost,
Accessability: Powered by ER, Cosmic.

However:
1) every point of damage stopped ALSO drains 2 points of ER.
2) If you run out of ER, the force field collapses immediately. If you
ran out of ER because of the cost of stopping damage, you stop the last
point of damage you can pay full cost for, and the rest blows through.
3) If the force field is destroyed, it can be "recast" for 2 ER, and it
immediately has 4 ablative DR available again.

Normally as a GM I'd be really reluctant to allow #3, as it sort of
makes Ablative pointless, but #1 and 2 make it really relevant again. 

--
Emily Smirle
Zwischen Leber und Milz, passt immer noch eine Pils.
Denn wo frueher mal die Leber war, ist heute eine Mini-Bar.