The whole point of this post is to compare the 'old' way of resolving magic resistance (unopposed rolls) to the new way in the Players Update (opposed rolls), as there is a major difference in the way the two play (as well as many minor ones). I am not saying one is better than the other, just that they are different. Most of the following observations are a direct result of my having run a number of high powered magic duels in attempting to come up with rules to use opposed resistance rolls rather than the original system. In doing so I realized I actually liked the original system (I thought I didn't upon reading it - amazing what actually playing the system can do).
In summary the original system uses unopposed rolls - the caster rolls against his skill for a simple success/failure result, and if he succeeds the target rolls against his appropriate resist skill (dodge, persistence, or resilience depending on the spell he is resisting) in a simple unopposed test. A person with a high resist is going to be very hard to affect without overcharging spells.
The new system involves resolving the casting as an opposed roll between the casters skill and the targets resist. Basically the attacker rolls and the defender then tries to beat the attackers roll in an opposed test if it was successful.
Whew. Finally, on to the major difference. Duels between moderate skilled (50%-60%) opponents play pretty similar between the two systems. The differences occur when casters have high skills. For the examples coming assume all participants have 95% in all relevant skills (casting, resist, etc).
In the old system in a high powered duel the participants NEED to overcharge. Casting a 2 point befuddle has almost no chance of working without overcharging, so the casters have to start throwing 5-6 point befuddles around. Overcharging by four gives the target -40%, so he will have to overcharge to get his resist back up (it will take 8 points to get back to 95%). A whole kind of bidding game with MP is involved (how many points to overcharge while still having a good enough chance of success). Often the contest will come down to he who loses his stores of MP first loses. I find it has very epic feel, with powerful magicians throwing huge amounts of magical energy at each other in spectacular fashion.
In the new system the befuddle is opposed, so if both magicians are of equal skill (say 95%) the casting has a 50/50 chance of succeeding or failing without any overcharging. This is actually more similar to earlier RQ editions, where spell resistance was a POW vs POW roll on the resistance table - if both participants had a POW of 18 a base spell would have a 50% chance of taking effect. Actually, also using the Players Update rule the resist failing the opposed test but still being a simple success casing all overcharge effects to be lost makes overcharging likely to be a waste of points against a high resist (unless you overcharge a LOT) - it works better against low resist targets.
So that is the major difference: in the old way high level casting requires a lot of MP, in the new way it doesn't. It is a matter of taste really. They both work, and there is a logic to both systems. I find the old way a bit simpler in execution, but the new way is by no means too complicated - my only concern is that the target should have to declare how many points they are overcharging before seeing the casters roll.
Some people have proposed using opposed rolls and doing away with overcharging all together - this can work as well though requires also coming up with alternative ways of dealing with counter magic and dispel magic.
I am going to move on to the more subtle differences in another post as this one is long already.
In summary the original system uses unopposed rolls - the caster rolls against his skill for a simple success/failure result, and if he succeeds the target rolls against his appropriate resist skill (dodge, persistence, or resilience depending on the spell he is resisting) in a simple unopposed test. A person with a high resist is going to be very hard to affect without overcharging spells.
The new system involves resolving the casting as an opposed roll between the casters skill and the targets resist. Basically the attacker rolls and the defender then tries to beat the attackers roll in an opposed test if it was successful.
Whew. Finally, on to the major difference. Duels between moderate skilled (50%-60%) opponents play pretty similar between the two systems. The differences occur when casters have high skills. For the examples coming assume all participants have 95% in all relevant skills (casting, resist, etc).
In the old system in a high powered duel the participants NEED to overcharge. Casting a 2 point befuddle has almost no chance of working without overcharging, so the casters have to start throwing 5-6 point befuddles around. Overcharging by four gives the target -40%, so he will have to overcharge to get his resist back up (it will take 8 points to get back to 95%). A whole kind of bidding game with MP is involved (how many points to overcharge while still having a good enough chance of success). Often the contest will come down to he who loses his stores of MP first loses. I find it has very epic feel, with powerful magicians throwing huge amounts of magical energy at each other in spectacular fashion.
In the new system the befuddle is opposed, so if both magicians are of equal skill (say 95%) the casting has a 50/50 chance of succeeding or failing without any overcharging. This is actually more similar to earlier RQ editions, where spell resistance was a POW vs POW roll on the resistance table - if both participants had a POW of 18 a base spell would have a 50% chance of taking effect. Actually, also using the Players Update rule the resist failing the opposed test but still being a simple success casing all overcharge effects to be lost makes overcharging likely to be a waste of points against a high resist (unless you overcharge a LOT) - it works better against low resist targets.
So that is the major difference: in the old way high level casting requires a lot of MP, in the new way it doesn't. It is a matter of taste really. They both work, and there is a logic to both systems. I find the old way a bit simpler in execution, but the new way is by no means too complicated - my only concern is that the target should have to declare how many points they are overcharging before seeing the casters roll.
Some people have proposed using opposed rolls and doing away with overcharging all together - this can work as well though requires also coming up with alternative ways of dealing with counter magic and dispel magic.
I am going to move on to the more subtle differences in another post as this one is long already.