Floating disc is a handy spell to magically carry items around for you. They let you keep more stuff to sell or use without worrying about burden. It’s not advisable to put truly precious items on them, but they’re perfect for the loot you gain in day to day adventuring. They are particularly useful to magical characters, who traditionally have low strength and up to three sets of gear to carry around.

If discs have major drawbacks it’s that they don’t follow instantly, so they don’t work at all with ‘shoprun’ commands. They also dump everything on the ground if you forget to recast the spell to maintain them. Legends speak of a ‘disc trick’ ability that would let thieves get all the items on someone’s disc, but otherwise it’s impossible for anyone but the owner to access them.

Looking at a disc will show how far it’s hovering off the ground. This has no meaning except to tell you the remaining minutes left in the spell before it collapses. One inch equals one minute remaining duration.

The in game help reads:

No saving throw.
Casting time: 1 round.
Type of spell: neutral spell.
Affecting stats: wis/int.
Cast type: teleportation.
Spell point cost: 44.
This spell creates a disc that floats in the air behind you.
You can put things in it so that it carries them for you.
Maximum duration for this spell is LVL/2 minutes,
but in any case it will last at least 2 minutes.
You can also update the floating time by casting the spell
at certain disc. Floating discs are known to be unstable.
You can refer a floating disc with "<owner>'s disc", or
"my disc", which works for the owner.
If mud crashes, you lose the items on the disc.  POOF.
Note:  You can 'dissipate' or 'dispel' your floating disc
if you wish to end the spell prematurely.