When you play a site with a Trap X ability, it enters the realm face-down. Based on the trap’s threshold, place a matching draft site (, , , or ) on top of it with the back of the trap site partially visible. Treat the trap site as that Ordinary draft site while it’s face down.
As an activated ability, you may pay X to flip the site face up and resolve its Trap effect. You cannot activate a Silenced or Disabled trap site. If a Trap becomes Silenced or Disabled during activation (e.g. with a non-Ordinary trap), the activation still resolves.
There are other effects which can be applied specifically to Trap cards. To “Disarm” a trap means to turn it face up without resolving its Trap ability, and to “Reset” a trap means to turn it face-down. To “reactivate” a trap means to activate its trap ability while it is face-up, paying the mana and controlling the effect while it is resolving.
If an effect causes you to “reveal and play” a trap site, e.g. , you still reveal it, and then it enters place face-down.