Subarmalis or gambeson?

[Adventurous Artisan]

The best person to ask is Rod Walker. He has been jousting for years. At one event he attempted to recreate 13th century equipment as accurately as possible. He wore mail with just a lined tunic underneath and his opponent wore a light felt tunic under mail and nothing else. They were both solidly hit multiple times with lances and swords from horseback and neither of them suffered anything more than bruising.

I've chatted with Rod Walker about that experience as 13th century is another one of my periods.  That man is the real deal.  He's putting together a pretty cool Roman Cavalry kit at the moment.