there's been some good advice on this thread and im solidly with Sir_Russell regarding his feelings on safewords but im surprised that so far almost everyone has said bondage doesnt hurt!

it shouldnt and generally doesnt but as with anything things can and do go wrong on occasions and especially for someone new its important to keep that in mind.

all it takes is for a slight misjudgement of tightness either too tight or too loose (too loose will work the rope around) a knot or the tie in the wrong place over a nerve,ligaments for example,preferably you need to have some knowledge of the anatomy beforehand.
and no matter what the tie,where the tie or even how tight the tie there is a real risk of nerve damage.

even such things as tiredness can affect how your body will react,ive been in complicated ties for lengths of time often longer than the usual 'recommended' timespan and spaced out to the eyeballs and as snug as a swaddled baby (rope subs will know what i mean by that *g*) but ive also on a rare occasion or two been in basic ties and begun to ache fairly quickly.

i know a very experienced and good rigger and he would be the first to tell you never for one minute make the mistake of believing bondage to be safe or pain free.

bondage is actually one of the most dangerous activities in bdsm,remember that originally bondage was designed for the capture and torture of prisoners in japan and while it has been adapted over the years particularly in the western world the principles and most basic ties are still the same.

its the best thing the japanese ever invented