Counter spells

[Bellberith]

Can a spell counter another spell that is similar to it though not exactly the same?

Like can a ray counter another ray (no matter the type) like scorching ray being countered by a ray of enfeeblement.

Also is there any way to counter a spell as an immediate action instead of taking your turns standard action to ready a spell.

[tyckspoon]

First question: No. To counterspell, you must use either the exact same-named spell (metamagic'd versions are ok, tho- Silent Ray of Enfeeblement still counters Ray of Enfeeblement and vice versa), Dispel Magic, or a spell that has a special note allowing it to counter things, such as [Light] and [Dark] spells countering each other.

Second question: Yes, there are several. There's the Reactive Counterspell feat, the Divine Defiance feat, the Battlemagic Perception spell, and a small handful of items relating to countering, including the Ring of Counterspells and Spellblades (for a single specific spell only) and the Ring of Spellbattle (which doesn't technically counter, but re-targeting a spell usually has a similar or better end result.)

[lsfreak]

Of those listed, Divine Defiance is the best for making a dedicated counterspeller (especially because Inquisition domain gets you a +4 to your check). Battlemagic perception, the rings, and so on are better for emergencies rather than making counterspelling your main schtick.

There's also nocturamancers, who get a class ability to do immediate-action counterspells, and a mystery that acts as an immediate-action counterspell. That requires being a shadowcaster, though, which isn't very good without houseruling (and in addition to all the problems that come with being a theurge, shadowcaster is probably one of the most painful classes to play at low levels).

And if you go cerebramancer, you can use linked synchronicity shenanigans to get extra readied actions per round that are effectively immediate-action counterspells, but that requires your DM allowing synchronicity shenanigans (and is a theurge as well).

[holywhippet]

The improved counterspell feat lets you counter with any spell from the same school provided it's at least one level higher. Since many similar spells are of the same school that will come close.