ATTACK or DROP break and remove fragile items from play.

In emulation of a certain annoying aspect of the original Adventure, in which there is a Ming vase that cannot safely be dropped:

"Ming Vase"
A thing can be strong or fragile. A thing is usually strong.
Instead of attacking or dropping a fragile thing:
   now the noun is nowhere;
   say "[The noun] breaks into thousands of pieces!"
The Cave is a room. The Ming vase is carried by the player. The vase is fragile.

We could also implement an additional refinement from Adventure, that a fragile thing is safe if dropped when there is a cushion nearby.

The pillow is a portable supporter. It is carried by the player.
Instead of dropping a fragile thing when the pillow is in the location: try putting the noun on the pillow instead.
After putting a fragile thing on the pillow:
   say "You set [the noun] down gently on the pillow."
Test me with "drop pillow / drop vase / get vase / get pillow / drop vase".
Test me with "drop pillow / drop vase / get vase / get pillow / drop vase".
Cave

>(Testing.)

>[1] drop pillow
Dropped.

>[2] drop vase
You set the Ming vase down gently on the pillow.

>[3] get vase
Taken.

>[4] get pillow
Taken.

>[5] drop vase
The Ming vase breaks into thousands of pieces!

In this rule, the pillow is the second noun; if we had a general rule about setting fragile things on soft things, we could say "You set [the noun] down gently on [the second noun]." for the same effect.

If we wanted to be more refined, we would provide extra code so that breaking a container or a supporter would leave behind their contents. We will see how to do that later.