If you want smackdown tricks - here goes:
Note - not all of these tricks work in all situations - but they are very very nifty.
Ye old top 10 tricks to Smacketh Downeth Munchkinism, Power Gaming PC's. Min/maxers, or just to be a Mean GM and take the kiddie gloves off.
1. Dispel Magic (lower level), Greater Dispelling (mid levels), and Mordenkainen's Disjunction (high levels)
- this goes a long way to ending Magickal tricks and magic items
2. Ye Rogue - with all those sneak attack dice - How can I deprive an opponent of His dex bonus to AC ... Oh let Me count the ways... Worse - use a wizard turned assassin.
3. Divide and Conquer:
Take control of PC mind - then use Munchkin PC against rest of party. Much fun ensues as PC's are forced to save friend without killing Him:
suggestion, confusion, dominate person, dominate monster, and similar spells work wonderfully in this regard.
4. Irregular terrain:
Get the PC's airborne, underwater, underground, or even on another plane. Anti-Magic, or Dead Magic(FRCS) areas work as well. Sometimes, the terrain itself can be hostile (see plane of fire - MotP) They must adapt - or die.
Suggestion: do NOT use the players use the cheesy "planar adaptation spells". Make them think and be creative.
5. Traps, Tricks, and other Troubles.
One need not use a monster to kill. Several good books on traps have existed over the years; the grimtooth series was comical but had some serious suggestions as well. There is an upcoming book from WotC on this topic as well.
6. Ye old wand of enveneration - energy drain spell; or energy draining SLA or SU monster. (Bring out yer dead!!!) Preferably make chief evil villan a necromancer with this item. Proceed to zap depleted PC's without mercy.
7. Feeblemind - (enough said)
8. Why is it the PC's ALWAYS seem get the drop on the baddies? Use an ambush.
Lower levels:
While you are walking down the path... (hidden NPC hobgoblins makes attack rolls against random PC's) a hail of arrows comes at you. - AMBUSH!!! -
Mid Levels:
Open up with a fireball or magic missile for the "direct" solution - Alternately a web or entangle spell can be used for the "indirect" method.
High levels:
**** Reqest is for mid level smacks only ****
Of course; smart NPC's are going to shoot at unarmored or lightly armored (wizards, monks, rogues, sorcerers) or characters that advertize spellcasting power (clerics who carry their holy symbols openly) first, depending on discrminatory nature.
9. Strike while unseen:
Invisibility and improved invisibility - in conjunction with points 2 and 8 make for very deadly situations
10. Use poisonous monsters, or poisoned blades.
Con poisons tend to kill outright, while poisons that don't strike at the constitution stat disable, rather than kill. Once a given character realizes what is happening - much fun ensues, depending on the poison used.