English: An image that shows the difference between strategies in subgame perfect Nash equilibria and plain NE's. The first player chooses Left or Right and the second player then chooses to be kind or unkind, however, following R unkind is a non-credible threat by 2.

This can be used as a very simple example of dynamic inconsistency in some Nash equilibria.

The extensive form game is made with the latex-package egameps, furthermore it's tweaked in Inkscape and the table is pasted in from a simple OOo screencap - if someone feels like vectorizing the normal form representation it's just fine with me.