OK, so I have volunteered for a local gaming charity event. If I get picked to run a game, I am thinking about doing a HARP game. (Finger's crossed.) In order to make things really easy on myself, I am thinking about having the player's roll for everything, even when getting attacked. Not like they use their attackers OB, but like they roll a defense roll using their DB.
Example: Groff, the fighter, is getting attacked by an orc. The player rolls the dice and adds their DB (including any OB they added). Now, my problem here is: what are rolling against? Do I say that the attacker rolled a specific number which is added to their OB and use that as a target number? In that way, the resulting number is looked up on the appropriate attack table to determine the results. Does that sound workable? If so, what is the number I should use? The average of a d100 is 51, should I use that? Or is 55 or even 60 more appropriate?
Also, is there another way to do it that is easy?