In JiuJitSu, there's the sleeper hold, choke hold, arm lock, ankle lock, etc... now, do all these have counter measures? Or if they pull this on you, you're dead meat?
Yes, to some extent. Depends on the technique. Some things can be escaped, others can't. Their position, your position, strength, flexibility and skill all play a part. With the right technique once it is applied properly you're done, the trick is to not let it get applied. Like a punch to the face, you can defend it right up until it lands, after that there is nothing you can do as you've been punched.
I'll parrot Mr Green to an extent here, its the practitioner who makes the technique. Theres always an out if your significantly better than the other guy Col
I'll parrot the parrot! They've summed it up really. Once its on properly the other person may well be done for unless they're stronger or very skillfull. In which case they should have countered before the lock is properly applied. Thats really when you should be aiming to counter.