RewriteEngine On 

RewriteRule ^videos-([0-9]+).xml$ ?option=video&p=$1 [NC]

RewriteRule ^video_tags-([0-9]+).xml$ ?option=tag&p=$1 [NC]

RewriteRule ^video_categories.xml$ ?option=video_categories [NC]

RewriteRule ^games-([0-9]+).xml$ ?option=games&p=$1 [NC]

RewriteRule ^game_tags-([0-9]+).xml$ ?option=game_tag&p=$1 [NC]

RewriteRule ^game_categories.xml$ ?option=game_categories [NC]