What is the extent of the glamor power of a powerful spirit? Could a spirit convince a sec. guard that the guard was holding valid documents for something? Could the spirit use glamor to make a truck carrying a bunch of C12 appear to be a truck carrying a bunch of fish? Would glamor work on a rigged security system?

Also, assuming that a free spirit somehow had this ability, what kinds of restrictions would you place on it?

Hmm, maybe within Force meters to start the effect (no glamour over cameras) and maybe force hours to reamin convinced. (Clasically galmour wears of in 'a while')

AS for the size of the effect, maby make the spirit roll something to determine how convincing it is? So you go from: this is my dirver's license, to you don't need to see my driver's license, to I was never here, to your wallet was never here either.

So treat it like an area affect (multi-target) spell-like ability to make trid phantasm at a force equal to the spirit's force, with TN equal to, say, the target's willpower, and number of successes denotes how convinced they are? Could the spirit use glamor to convince someone that, even though they're standing in acid up to their knees, they're actually walking on fresh, springy grass? And if the spirit was on your side, could it use it's glamor ability to convince you that you hadn't taken any damage, and thereby negating TN modifiers for damage?

This isn't an entirely hypothetical situation... One of the PCs in my group managed to get the true-name of a fairly powerful spirit that has the glamor power, and now the PC is trying to find ways to use the power, and I'm trying to find game mechanics so that the power isn't game-breaking.

Have the spirit bust his ass... there are ways it can get him without directly bumming him!

Personally, I wouldn't let the glamour be used for 'combat' effect since 'clasically' it's much more a social whammy. (Note that you could probably use to convince someone they were not wounded, or that there was no traffic, or no pit, or the edge of the building is really a few feet farther away...)

He feeds it karma to make it happy. He teaches it skills. 90% of the time, he lets it do whatever the heck it wants to do.

Basically, he's doing everything in his power to keep it happy, without letting it go. On the other hand, other mages/shamans he's met who've found out about his bound free spirit have been getting pissed off at him of late - kind of a major social blunder.

Hestaby was expecially put out.

He's considering freeing it, but he doesn't want to lose all that power, so he's thinking of having the spirit get the hidden life power in him and then letting the spirit go free