RewriteEngine On
RewriteRule ^category/(.*),([^/]*).html$ /index.php?p=category&what=$1&page=$2 [L,NC]
RewriteRule ^category/(.*).html$ /index.php?p=category&what=$1 [L,NC]
ReWriteRule ^game/(.*).html$ /index.php?p=game&what=$1 [L,NC]