I have the distinct impression this is going to come up shortly in a game I'm running. Basically there is a prisoner being held, bound by a chain attached to a thick metal band of iron around one ankle which leads to a metal ring in the floor. He has about ten feet of lead.

I'm curious how people think a character in this predicament would be penalized with regards to combat. Obviously they couldn't get up to a full run with that lead length and with a chain around one ankle. I think the closest point of reference in the condition summaries is Entangled which is basically a -2 penalty on all attack rolls and a -4 penalty to Dexterity. I'm not sure that's appropriate given that the character is only bound at the ankle.

I'm curious what people think of this and if such a penalty seems fair or unfair or otherwise. I have looked online and through a few resources I have but I can't seem to satisfy my thoughts on the matter.

entangled rules actually seem pretty fair to me, but I'd lower movement speed as well,

I wouldn't penalize them at all in combat. Having a chain around one ankle probably wouldn't impede you that much at all apart from limiting how far you can move before falling over. Also, the fact they're stuck in a 10 ft radius, presumably unprotected and unarmed makes them a pretty soft target as it is - that's penalty enough.

It would significantly hamper their maneuverability, and thus their ability to attack and to defend themselves effectively, but only near the edges of the chains' limits. I'd suggest Entangled for representing that.
Closer to the middle of their range? It probably won't hurt them much, at most, maybe making it a bit easier to trip them. (apply a +2 circumstance bonus to trip attempts against them)

Yeah, unless they're near the end of the line, they shouldn't be hampered too terribly. Maybe a -2 to dexterity to represent trying to keep from getting tangled up in the chain. At the end, entangled works pretty well.

To me the entangle rules imply that the character is bound more completely than around one ankle so the full out penalty for entanglement seems to be a bit on the heavy side. I think -2 to Dex and a +2 circumstance bonus to trip seems fair.

I'd half his movement and say he cannot take a 5ft step as part of a full round action (let him make a strength check if you're feeling generous). Then hit him with a -2 or -4 to dex based skill checks and jump, but not his ability to dodge blows since he can do that without moving from his square. A +2 plus two circumstance bonus to attempts made to trip him sounds fair. However, if he was strong, the character may be able to use the chain as an improvised weapon and or entangle others with it. That's what Bruce Willis would do

Second vote here. Unless you're talking about a massive logging chain, odds are this chain is little thicker than what one would use to tether a large dog. Movement wouldn't be hampered until the prisoner reaches the end of the chain - at which point movement will stop, possibly causing him to fall prone.

"Entangled" generally refers to being severely hampered by such things as thick underbrush, giant spider webs, a net, or something similar.

Again: the prisoner is chained to the floor, unarmed and unarmored. At low levels, this is sufficient. At higher levels, well, the BBEG is just asking for you to escape if that's all he's using to restrain you.

At higher levels, if escape is that obvious, it's probably a bad idea.

I'd give a -2 to Dexterity. Entangled, like the Dr. said, is for things that completely hamper limbs, like a net. A chain on an ankle shouldn't affect attack rolls. It would only prevent a charge.

You could integrate skill-based challenge into it, in that the chain is light, but it is still there, meaning it can get caught up in moving feet. If the character moves for a few rounds without being careful (DEX check or some appropriate skill like Balance or Knowledge: Avoid Getting Caught by Chain), then start applying penalties to either AC, Dex, attacks, etc, or any combination thereof.

Also, limiting speed to 20 in the area reachable is appropriate, since the character can only move 20 feet anyway, from one end of the circle to the opposite. Entangled as it is seems a bit much for the situation, and being bound does, as mentioned, mean the character probably isn't ready for a fight anyhow unless they are a Vow of Poverty Monk (not in d20 Modern, but you get the point, I figure...).

I guess that's something to think about as far as resolving it.