Adjective for "something in which you always find something new"

Question

Or alternatively, "something in which you're always able to find/discover something new".

An example:

A book, which you read multiple times, and every time you read it, you

• see a whole new aspect of something, e.g. about the plot,
• notice some detail that you haven't noticed before,
• understand some joke you haven't understood before.

... and other features that make a book more rereadable, or timeless.

Another example:

A computer game, which you play over and over, and you always seem to

• discover new possibilities about what the game allows you to do,
• find new locations in the in-game world that you haven't found before,
• notice some intentionally hidden message or joke, i.e. an Easter egg.

... and other features that increase replayability.

Is there a single adjective describing this property?

Answer 1

I would describe it as having depth or being deep; or extensive (or extensively replayable, for a game), if it covers a great range of things, or gives you a lot to do or think about; or perhaps profound if it causes you to keep pondering new things.

Answer 2

"self-renewing"

renew - (v tr) - to make (something) new, fresh, or strong again, (v intr.) to become new again. TFD

• Self renewing people require times of solitude and quiet. (The Self Renewing Adult)
• The main outcome of such training is a self-renewing system which could...(Leaders and Managers)

Answer 3

"ever-fresh". Ever-fresh. Ever-fresh? Ever-fresh!

Answer 4

When things are dynamic, new changes and fresh energy are always in the air.

Answer 5

Alive

Having interest and meaning:

His history lessons are alive with fresh perspective.

Alternately,

Avant-garde

ADJECTIVE

Favouring or introducing new and experimental ideas and methods:

Answer 6

Fertile

adjective
1. bearing, producing, or capable of producing vegetation, crops, etc., abundantly; prolific: fertile soil.
2. bearing or capable of bearing offspring.
3. abundantly productive: a fertile imagination.
4. producing an abundance (usually followed by of or in): a land fertile of wheat.
5. conducive to productiveness: fertile showers.
_{Source: dictionary.com definition for “fertile”}

Prolific

adjective
1. producing offspring, young, fruit, etc., abundantly; highly fruitful: a prolific pear tree.
2. producing in large quantities or with great frequency; highly productive: a prolific writer.
3. profusely productive or fruitful (often followed by in or of): a bequest prolific of litigations.
4. characterized by abundant production: a prolific year for tomatoes.
_{Source: dictionary.com definition for “prolific”}

Productive

adjective
1. having the power of producing; generative; creative: a productive effort.
2. producing readily or abundantly; fertile: a productive vineyard.
3. causing; bringing about (usually followed by of): conditions productive of crime and sin.
_{Source: dictionary.com definition for “productive”}