Open and Closed States

A chain depends on the current game state open or closed. Whenever a player performs an action then the game state is closed. However if nothing is going on and neither player wants to do anything then the game state is open. For example the turn player has a chance to activate an effect and does not wish to and the other player wishes to do nothing then no chain is currently being formed.

If the game state is open then a player can activate one of the following effects:

• Normal Draw: During the draw phase
  
• Normal Summon or Set
  
• Perform a summon that does not start a chain
  
• Attempt to move to the next turn phase
  
• Declare an Attack
  
• Activate an ignition effect 
  
• Activate a Spell Speed 1 card
  

If the game state is closed then only Fast Effects can be activated.

Here's an image to help you comprehend it all:



If you have any questions post below and please note that this is the first in a multi part series.  Also they may be lesson pending on the interest.

Note: this was done quickly, if you wish for anything to be added or discussed in further detail then let me know.