My idea was to have a combat school where players went, were assigned a room with an npc of appropriate stats and were able to train combat skills.
I was thinking there would be rounds. A round would be won when npc or player reached 1 hit point. There would be no death, neither player nor npc would drop below one hit point.
The next round would not start until the npc was back at full hit points and the player attacked the npc. The winner of each round would be paid by the loser of the round. Since the npc would be at least equal to the player, the npc would win part of the rounds.
If the player did not have enough coin to pay upon loosing the round, the player would be kicked out of the training school with 1 hit point and 0 stamina. Of course, the stats would regenerate normally after being thrown out of the school.
It would be nice if the rooms were each separate instances, that way the number of players who could train at one time would not be limited to a set number of rooms.