"Critical Hits" are open content right?

[0-hr]

I can't find an explanation of a critical hit in the SRD (I'm using the Solvelior HTML). In the Player's Handbook, it's in a side bar on pg.140. Where is it in the SRD? Is it just my copy that is lacking, or is that material really not open content?

 

[DarkMaster]

I can't find an explanation of a critical hit in the SRD (I'm using the Solvelior HTML). In the Player's Handbook, it's in a side bar on pg.140. Where is it in the SRD? Is it just my copy that is lacking, or is that material really not open content?

Answer is in "combat I (Basic)"