This isn't a good idea for the forums as a whole. However, it could certainly help on on-topic, civ-related sections, as the OP suggests, and could be worth a try if possible.
There are posters who specifically lie to new players just to troll them, and the moderators seem to refuse to infract this on, say, the civ4 boards. If other action isn't being taken to clean this up, a like system couldn't hurt (So, say, when a new player posts something like "how do I do this thing in my city" and the guys giving lies that will cause the game to do other things aren't voted up, they will be discouraged)
There are posters who specifically lie to new players just to troll them, and the moderators seem to refuse to infract this on, say, the civ4 boards. If other action isn't being taken to clean this up, a like system couldn't hurt (So, say, when a new player posts something like "how do I do this thing in my city" and the guys giving lies that will cause the game to do other things aren't voted up, they will be discouraged)

or some spammish comment to garner a bunch of "Like" ratings just so people can spam or troll without being caught at it. Then the complaints start coming in to the moderators, and the task of sorting it all out begins.

