[@vancexentan]A 10-foot square that triggers when touched, with settings available around who can trigger it (a trap could be set to only activate for servants, or not to activate for designated allies, for example). As for the effects that can be produced, the available settings are an explosion, a knockout wave, restraining chains, and a petrification type effect (only 1 setting per trap). The explosion is on a level that would seriously injure a normal human. The other three could be resisted by mages, especially if they saw it coming (I forget exactly how this works, but it's the reason Shirou and Rin stayed conscious when Rider knocked out the school). None of these would bother a Servant much unless they were physically very weak, and a descent mage should be able to negate all but the explosion easily. They're really more utility, since August could dispel the chains or petrification at any time, and gets a psychic notification when one goes off.

Now that I've had to go into detail, it seems more powerful than the simple idea in my head. Thoughts?