I couldn't find this in the solved questions thread so I'm asking it here. Can you plant D-Charges on a piece of scenery and use an ARO to detonate them when an enemy troop walks past, causing them to make an armour roll/take damage?
D-Charges don't have a Template, so they're never going to harm anything except the target they're planted on. In addition, AROs can only be declared against the Active model, so you can only ARO detonate the D-Charge if it was planned on the Active model.
Note the last line of this FAQ (emphasis not added by me), AROs must target the Active Trooper, this includes a detonate D-Charges ARO. N3 Frequently Asked Question FAQ Version: 1.1 Q: When can an Engineer detonate a D-Charge? A: A trooper with the Engineer Special Skill may, in the Active Turn, remotely detonate, without range or LoF restrictions and without a Roll, a D-Charge previously planted by themselves or by any other trooper from their army. In the Reactive Turn they may detonate a D-Charge if either of the following is true: He has Line of Fire (LoF) to a trooper being activated by the Active Player. Or if the trooper activates within his Zone of Control. AROs must choose the trooper activated by the Order as their target.