[RPG] When is an object made of other objects

dnd-5eobjectsspells

I've read What is considered an object? and Can Telekinesis be used to manipulate liquids?

It still seems pretty unclear though to me, specifically when I read:

For the purpose of these rules, an object is a discrete. inanimate item like a window, door, sword, book, table, chair, or stone, not a building or a vehicle that is composed of many other objects.

A window is glass and pane, a sword has its handle and blade, a book its leather binding and pages…

When does an object become composed of other objects? This seems very contradictory to me. Most objects aren't made of a single material. A basic bridge is wood and rope. A basic candle is wax and wick. A basic chest is metal and wood.

And here we have a tweet that makes things even more broken – https://twitter.com/Scyllan8/status/801488065600561152

@JeremyECrawford wizzard in my group wants to use the reduce spell on all locked doors to bypass them is this valid?

@JeremyECrawford
23 Nov 2016
Replying to @Scyllan8

I would ask the wizard which part of the door they're trying to reduce. Most doors are made of multiple objects.

Okay so we have to specify the binding vs the pages in the case of a book, or the wood vs rope in the case of a wooden bridge… but if this is accurate then we could shrink the blade of a sword but not the handle causing it to fall out.

The spell I'm actually focused on is Enlarge / Reduce.

Best Answer

When the DM says so

It's up to DM when to divide one big object into smaller ones. DMG page 247 suggest to do it when the object size is Huge or Gargantua:

If you track hit points for the object, divide it into Large or smaller sections, and track each section's hit points separately. Destroying one of those sections could ruin the entire object.

DM can decide on their own discretion, as it was in the Jeremy Crawford's door example. It can be used to give more choices (consequently, more possibilities) to the players. For example, you can shrink the door's lock only, in order to leave the door itself functional.

Players should not care about this though. As a player, you just say "I cast Reduce on this bridge/lock/sword/blade".

The DM either

  • accepts your announcement and says what happens next
  • asks you for the details
  • or explains "you can't do this, because/until..."

Also, good DM always find an in-game explanation, instead of just saying "because the rules, you know".