In Pathfinder there are a few spells that are effectively polar opposites, and as such have the text
counters and dispells [opposite]. The rules for counter spell are spelled out fairly well, but I'm not sure about the dispelling. If I use a opposed spell that would normally allow a saving throw and spell resistance to dispell it's opposite, does that require a spell penetration check, allow a saving throw, or simply happen?
For example, the party is fighting a Wizard with Slow on his list. The party casts Haste. The next round the Wizard casts Slow on the party to dispell Haste. What rolls if any, are required for the dispell to be successful.