From the Back Cover:
The Ultimate Games Designer's Companion is the fourth Supplementary Rulebook of the Ultimate Series, compiling some of the best and most original rules and ideas for the d20 system. Designed to be seamlessly fitted into any d20 games system, these sourcebooks offer the best of the best that have appeared in terms of rules and options for Games Masters and players alike. As well as presenting a plethora of information from some of the most prestigious names in roleplaying, new material is littered throughout, all easily integrated into your d20 games.
For those who wishes to add more realism to their games options are provide to add a bloodier edge to their games. While, for those who wish to inject a little bit of Hollywood into their campaigns, more outrageous ideas allow for all the excitement of the silver screen to hit the gaming table.