Combat in 3Deep was always intended to be very interactive. The aggressor would attack, if they hit, they would roll the location. The defender could then try and block with their shield if they had one. Then the attacker would roll damage and knock back. The defender then deducts shield and armour from the damage and applies it to their character. Both attacking and defending players are active all though the action.
The down side is that it can get slow.
To speed it up I have created this deck of cards. The video explains what each part of the card is for, but either as the GM running the combat, or in solo play, the cards make combat much faster.
I would still let players roll for their shields, just to let them feel that their dice rolls matter.