Compendium LvX
The Compendium LvX is the latest version of the Pokémon Rulings Compendium.
The direct link is:
You can view it, or download it as an Acrobat file for your computer or an iSilo file for your PDA.
Compendium EX
The Compendium EX is the archived older version of the rulings from PUI during the years 2003-2007, not for current use, but retained for research.
Compendium
The original Compendium is the archived older version of the rulings from WotC during the years 1999-2003. Again, these are not for current use, but are retained for research.
