What?
Grilles make no sense from a gameplay or RP perspective. They break muh imershuns by virtue of the fact that no one in real life uses grilles for this purpose, and they punish new players for being new. I imagine everyone reading this has run into an Egrille in their first few games, and taken a very nasty shock for their troubles. This is not because we're all idiots (at least not entirely) but because Egrilles are only found in this game, and are not a hazard that any person would logically expect. You only find out they're dangerous by being told or by hurting yourself. The alternative is a tool used by modern militaries and likely the USCMC as well, for protection of key points in colonial revolts or a prison station riot. Razor wire!
Summary (a quick, 2-3 sentence summary):
Instead of being able to build grilles, engineers can build razor wire. Razor wire deals brute damage, usually to the feet and legs, of any mob that walks into it. Like grilles, it can also be electrified by having a wire underneath it and behaves like an Egrille.
How does this benefit marines?
Razor wire deals brute damage to xenos, even if not powered. New players won't accidentally electrocute themselves, and if they do you can point and laugh because they knowingly ran into razor wire.
How does this benefit aliens?
Razor wire deals brute damage to marines,even if not powered. Prey walking with a limp from stumbling into razor wire makes for a wonderful new host. Razor wire can also be slashed apart slightly easier than grilles.
Details (Description of how you think this would work, the benefits, etc):
Remove grilles from the list of construct-able items and replace it with razor wire. Razor wire behaves like grilles currently do, marines can shoot through themand they can be electrified with a wire underneath them. They deal low-medium brute damage to the legs of anything that walks into them, and medium brute damage to anything that attacks them. To compensate for the additional damage to xenos, they can be ripped apart slightly easier than grilles.
UPDATE: Razor wire MK2
I realized that this suggestion will probably be denied since it is basically Egrilles with brute damage, and egrilles got removed because marines would build massive fields of them and shoot over them, slaughtering the aliens that desperately tried to break them down. In light of that, i've come up with a new plan for razor wire.
Razor wire cannot be electrified. It deals brute damage to almost any mob who walks into it. It can be be fired over like grilles, but can be slashed apart by xenos. The best way to destroy razor wire is with the help of a Prae, Rav, Queen or especially a crusher. Preas, Queens and Ravs can walk right through razor wire, though they take significant damage for their trouble. Crushers can bulldoze their way through razor wire entirely. They need a momentum of 10 to break the wire without stopping, and every layer of wire they break slows them down by 10. Doing this deals no damage, but if they are stopped by the wire it will deal damage, as they have gone from breaking apart the wire with their armoured heads to stumbling over the wire and getting caught, just like a Rav, Queen or Prae would when wading through the wire.
This means that razor wire is not able to be abused like Egrilles were. Its primary purpose is rapidly built area denial for T1 and T2s, allowing marines to defend FOBs in the early game with fewer men. This helps encourage marines to scout and attack instead of turtling in FOBs in the early game. Once the aliens have a solid base of T3s, however, razor wire acts merely as a deterrent and can be bashed through by aliens given time.
