One of the big things I have been doing while designing 101 8th Level Spells is playing around with partial effects (something that happens even if you make a successful saving throw). A good example of an existing spell that does this is cause fear. It’s a great piece of design, since Shaken is a condition that still allows you to do something while still causing a penalty for 1 round (though you can break this by having two cause fear spells hit one target which causes you to become panicked for one round but that’s only because Shaken stacks). So this became my design philosophy
"Include partial effects, but these partial effects have to allow a character to act and these partial effects can only last for 1 round."
Ability Damage, Ability Drain (1 point) Bleed, Blinded, Broken, Dazzled (really its too weak though) Deafened, Energy Drain ( rather 1 temporary negative level), Entangled, Exhausted, Fatigued, Flat-footed, Grappled, Prone, Shaken, Sickened, and Staggered
Confused is on the borderline along with Nauseated, because one only gives you a potential chance to act and the other only allows you a move action, so I often avoid them both.
There is also one unnamed condition in the Pathfinder Roleplaying Game, that I like to call Tormented (based on the symbol of pain) a –4 circumstance penalty on attack rolls, skill checks, and ability checks. This could easily become a –1 or -2 circumstance penalty on attack rolls, skill checks, and ability checks for one round.
Another one I am thinking about now is the effects of a bestow curse for 1 round we will have to see.
You have to be careful though so you don’t create a “Push [insert spell name] to win” with the caster spamming the spell every round to keep the monster under its thumb. Also while a wizard might not loose a lot when staggered a high level fighter does since he can’t make a full attack action. So I decided to use a nice piece of design found in Frightful Presence.
“After 1 round a subject that succeeded on the saving throw is immune to the [insert partial effect name] of that same caster's [insert spell name] for 24 hours.”
What do you think?