> For the complete documentation index, see [llms.txt](https://book.runesterminal.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://book.runesterminal.io/2.-origins/ordinal-theory-ordinals/rarity.md).

# Rarity

A natural progression of this numbering system is that people have begun to seek rare and desirable satoshis now that they can be individually tracked and transferred. 

Ordinal theorists can decide for themselves which sats are most prized, but certain periodic Bitcoin events lend themselves to a rarity hierarchy:

* Blocks: A new one roughly every 10 minutes
* Difficulty Adjustments: Every 2016 blocks (\~2 weeks)
* Halvings: Every 210,000 blocks (\~4 years)
* Cycles: Every 6 halvings (\~24 years), with halving and difficulty adjusting aligning

This yields the following rarity tiers:

* Common: Any non-first satoshi of a block
* Uncommon: First satoshi of each block
* Rare: First satoshi of each difficulty period
* Epic: First satoshi of each halving epoch
* Legendary: First satoshi of each cycle
* Mythic: First satoshi of the genesis block

The degree notation visually denotes an ordinal's rarity:

```
A°B′C″D‴
│ │ │ ╰─ Index of sat in the block
│ │ ╰─── Index of block in difficulty adjustment period
│ ╰───── Index of block in halving epoch
╰─────── Cycle, numbered starting from 0

```

Some examples:

1°1′1″1‴ - Common

1°1′1″0‴ - Uncommon

1°1′0″0‴ - Rare

1°0′1″0‴ - Epic

1°0′0″0‴ - Legendary 

0°0′0″0‴ - Mythic


---

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