What are some easy ways to make you opponent "Helpless" in combat?

[Kimi11]

As title really.

How would you go about it with out using magic; mostly to get a 'Coup de Grace' attack with easy. No points for guessing that I'm looking to abuse a x4 critical weapon. And semi-related, can you Power Attack on a Coup de Grace attack?

[PlatinumJester]

Drow Poison at low levels.
I don't think you could power attack since you automatically hit and don't roll an attack roll.

[Talic]

Poisons. Hold spells. Sleep spells.

No rule prevents power attack on CdG. You announce it before making an attack. A CdG is an attack. The penalty is irrelevant, since you auto-hit and confirm. Roll damage. Make save.

It's why most of my characters have a heavy pick. Great CdG Weapon, with the x4 crit, and they get the beautiful x4 mod even if they're not proficient.

[Uthug]

Why not a scythe? They're much much cooler.
What levels are you playing at? At the lower levels I guess sleep is fine.

[Khanderas]

As title really.

How would you go about it with out using magic; mostly to get a 'Coup de Grace' attack with easy. No points for guessing that I'm looking to abuse a x4 critical weapon. And semi-related, can you Power Attack on a Coup de Grace attack?

Pretty much everyone with a blunt weapon should be able to do a called attack when you got the same criteras as for Sneak Attack (dicernable anatomy and flatfooted/flanked) for a knockout with blunt and heavy object to the head. Don't thinkt that exists, probelbely because it could be heavily abused but that is what you are looking for anyways. (Either fort save or unconcious or a portion extra damage as nonlethal.)

Poisons are annoyingly flat in DnD, even before slow / remove poison, but I guess that is an option as well.

Saps is a classic one naturally.

Edit: Oh and explosives. Nappy time for most with a proper blast :)
Should be some critter with harvestable sleeping dust stuff on their corpses. Then again that may be more magic then you wanted.

[Kimi11]

The game is starting a level 6 and going to about 12ish. Level 6 makes poisons to become a bit limited (looks at +10 Fort save...). One way I was thinking of doing it was by pinning them in a grapple, but I'm not too sure about that being reliable.

[Newtkeeper]

The game is starting a level 6 and going to about 12ish. Level 6 makes poisons to become a bit limited (looks at +10 Fort save...). One way I was thinking of doing it was by pinning them in a grapple, but I'm not too sure about that being reliable.

And even then, a pin does not (I think) make you helpless enough to be CdGed. That would be too easy.

On the other hand, lob enough drow poison and they'll eventually fail a save.

[Person_Man]

Freezing the Lifeblood from Comp Warrior allows you to Paralyze enemies for 1d4+1 rounds if you successfully hit them with a Stunning Fist attack. It has a pretty high BAB requirement though.

There's the Coup de Grace weapon enhancement.

The Justicar PrC can hogtie enemies any with a Use Rope checks.

There's a feat that let's you coup de grace as a standard action. Can't remember the name off the top of my head though.

Also, many enemies are immune to crits, and thus coup de grace. So its not a great tactic to spend resources on to optimize.

[SyrkthTheGreedy]

As I've found so far, a fighter or rogue with a polearm (specifically a halberd) and a decent strength (and a tactical mind) can really output damage on opponents while putting them flat on their backs. Add in some feats concerning multiple attacks of opportunity and then you've likely hit your foe twice as much if not more than they've even had a chance to hit you.
Add in some sneak attack damage for the rogue and you're loking at some ugly damage dice while they're on the ground. That's as close to helpless as I can think of without actually putting them to sleep since even pinning isn't always an option.
Coup deGrace is alright, but it's difficult to pull off without magic or poison . . . or sneaking up while the PC's are sleeping . . . er, NPC's