Skara Devang cheated a bit with some otherworld technology (Atlantean, in this case). It was a simple little device. It went into the door frame of the entrance and when people went through it, it acted like a metal detector, only for all weapons. She'd hooked it up to her security network in the booth and her over all Network.
A program had about as many weapons as could think of, which was a god awful lot due to her life adventures, in the log that would compare and remove matching items on a person that walked into the bar. If they had an item that matched one in the log, the detector would simply teleport the weapons off the person and into one of a few different sized safes in the back of the bar.
When a person leaves, their weapons are returned via projection of the door frame's 'field' six feet outside the bar's entrance.
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Additional security includes a series of cameras throughout the bar and one outside by the doors. Each camera is of Derko make. Meaning that they are capable of seeing through most, if not all, magical glamors/invisibility spells and technological cloaking devices.
Each comer and goer also gets a specific color halo around their body to indicate a species/race. If a new color shows up and has no predetermined label: Devang will keep a closer watch on those individuals until a label is identified and programed to that color.
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Due to recent issues involving teleportation/shadow travel/sifting/etc. there have been renovations to take care of this major crack in bar security.
A complex series of powerful barrier and ward spells have been laid over the bar to ensure everyone stays in the space-time location they are in the bar at any given time. Preventing them from changing their location by any means beyond physical locomotion.
Green stickers, sifting (crossing a wrinkle in space-time to save time), teleportation (travel above or below space-time), and the like do not work in the bar. The Gate still does as portals are not effected.
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Also due to issues, most magic that is considered 'aggressive' or 'privacy invading' has been nullified by the same field that prevents teleportation. ________________________
There area set of trap doors in the security booth and behind the bar that lead too and from each location. Travel is done through the basement under the bar that is no accessible via the dance floor area. There is a tunnel out of the basement into a tunnel system that will lead to various places.
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If you get aggressive with those in the bar or the bar help, they reserve rights to beat your ass into the ground. All others will be tossed outside where they could give a shit less what happens.