# -- ex.com/condition/1 => ex.com/condition.php?id=1
RewriteRule ^condition/([0-9]+)/? condition.php?id=$1 [L]
# 301 -- ex.com/condition.php?id=1 => ex.com/condition/1
RewriteRule condition\.php$ condition/1\? [L,R=301]
RewriteCond %{QUERY_STRING} (^|&)id\=1($|&)
RewriteRule ^ex\.com/condition\.php$ ex.com/condition/1? [L,R=301]