Tenser's Floating Disk; poor-man's Immovable Rod?

[Iolo Morganwg]

"The disk is immobile while you are within 20 feet of it."

Sound like it could be used to bar a door at the very least!

[Felvion]

"The disk is immobile while you are within 20 feet of it."

Sound like it could be used to bar a door at the very least!

Due to strong 3.5 bias against it, i only yesterday read the spell's description! It's not a bad spell and could prove situationaly useful but i'd rarely prefer it over others...
In your case, i'd say pushing rules apply. It can hold up to 500 pounds before it breaks down so i'll set this as it's moving point. A guy with a strength score of 16 can push up to 480 so he could almost move it. Even worse, two guys with a str of 10 (mere commoners one could say) can push 600 pounds together. This leads to the assumption that it could hold back most guys at early levels but only if they come alone!
On the other hand, 500 pounds are nothing to sneeze at. Barring a door with it could save your party 1 or 2 rounds until they stack some other heavy objects behind that door, or give them enough time to find a strategy and/or prepare some actions against those who try to break through the door...

[Dalebert]

If you were going to rules-lawyer it (which I don't recommend), it can't be pushed. It's immobile. However, they could push downward on it and exceed the 500 lb limit and thereby make it vanish. It's not technically weight. It's something that applies an equivalent force as that much weight but you're getting into physics and sciency stuph which never mixes well with D&D. I'd let that work though.

[d20familiar]

It's immobile.
However, immobile =/= immovable. I'd read that part of spell description as "doesn't move under own volition" rather then as "cannot be moved ever".