There is no reason for the only hazards on maps to be explosives like the Fusion Coil. Destructible on-map items can produce more special effects than just explosive damage.
A Plasma Battery could produce a blinding flash upon destruction. The outer edge of the blast radius would only wash the color out of a player’s vision for a moment while a close range explosion would completely white the player’s screen out for a moment.
Unlike Fusion Coils or Plasma Batteries, a Sonic Pylon would not need to be destroyed to activate its special effect. Its special effect would always be active and it cannot be destroyed. The Sonic Pylon would reflect slow moving projectiles, like grenades, mortars, or rockets, that travel too close to it.
An Electrical Transformer, after being damaged, would begin arcing to players within range, gradually draining their shields through damage over time. To stop this effect, the transformer would have to be completely destroyed. For example, tossing one frag at the transformer would damage it, beginning the arcing effect. A second frag would destroy the transformer, ending the arcing effect.
Falling stalactites are similar to mortars in that they can deal damage from above. By damaging a hanging stalactite, and causing it to fall off the ceiling, the player can damage enemies behind cover. The stalactite is destroyed upon impact with the ground, ending its special effect.
What other Map Hazards could be introduced to Halo?
I liked everything but the Sonic Pylon. and I could totally see this happening as it seems to be that there will be more experimentation with interactive map objects.
Maybe something like fire? The flame thrower could set things alight, but it never stayed on fire. Perhaps there could be a battle damaged map, where certain things are on fire. Being too close to the fire will cause damage, like it did in Halo 3.
Perhaps there could be a map based in space, and if you break the windows, a vacuum is created and will suck out anyone near into space, until a shield appears. For example, here’s a situation where it could be used to an advantage:
'You run into a room in the space ship. There is only one way into this room. It’s a dead end. In this room are a few crates for cover, and a large window. Suddenly, two enemies appear from behind and begin firing at you. You rush and duck down behind the crates, but they are closing in on you. You then see the window, leading out into space. Seeing no other options, you begin to fire at the window. After a few rounds, the window begins to crack. Using your last grenade, you fling it a the window. The enemy players are right on top of you…
CRACK
WHOOOOSH
The window shatters open, and a vacuum suddenly appears. You manage to stay behind the heavy crates, far from the window, but your enemies are not so lucky. Being caught in the vacuum, the enemy players are swept off there feet and are hurled into space. “Double kill” the announcer calls out. After a few seconds, a shield is activated where the window once was, preventing any further damage. You get out of your hiding space, and move on to rendezvous with your allies…’
Sorry for the poor explanation. 
Having played some CEA over the weekend, I got to experience the breakable glass (windows and floors) in various Forerunner places (Assault on the Control Room, I believe). Break away floors could be neat…
But honestly I can’t top the exploding power cores. Just make 'em like Halo 3, not the laggy ones from Reach or the even laggier ones in Halo 4.
> Having played some CEA over the weekend, I got to experience the breakable glass (windows and floors) in various Forerunner places (Assault on the Control Room, I believe). Break away floors could be neat…
Can’t count the amount of times the breakable glass floor saved me from that mad Zealot… At least for a few seconds.
> > Having played some CEA over the weekend, I got to experience the breakable glass (windows and floors) in various Forerunner places (Assault on the Control Room, I believe). Break away floors could be neat…
>
> Can’t count the amount of times the breakable glass floor saved me from that mad Zealot… At least for a few seconds.
Yes. So much yes. That, and trolling him by leading him over it, breaking it, then filling the lower level with grenades.
Then again, it begs the question why Forerunners were so rubbish at making glass…
With regards to the obstacles, I think that these are great new ideas,(refreshing, since most people’s suggestions are just: “bring back so and so from Halo 3”) and with 343 integrating interactive elements to the Halo 2 Anniversary maps now, I think there’s a great chance these could be taken very seriously if 343 notices.
> there could be a map based in space, and if you break the windows, a vacuum is created and will suck out anyone near into space, until a shield appears.
Fantastic idea! I would consider the player’s ability to interact with maps to be one of Halo’s best features.
This idea is not only creative but plausible for the Halo universe. I like it a lot. Thanks for sharing.
> Falling stalactites are similar to mortars in that they can deal damage from above. By damaging a hanging stalactite, and causing it to fall off the ceiling, the player can damage enemies behind cover. The stalactite is destroyed upon impact with the ground, ending its special effect.
>
> What other Map Hazards could be introduced to Halo?
Waterworks from Halo 2 ring a bell? Anyone? Or maybe there were things like falling boulders on Beaver Creek.
the problem with having such things as your transformers and whatnot, is that people will just neutralize them at the beginning of the game so they can’t be hurt by them if it’s in an advantageous position. So having things like Plasma Batteries and Fusion Coils which are on set respawn timers are predictable ways of helping get people out of powerful positions. Like on Lockout… having fusion coils and such on the top of the snipe tower and BR tower are great for the people who just sit up there. If they are up there too long, the coils respawn and maybe someone can get a shot on them so they blow up and give an advantage to the people in the less advantageous positions.
I do see what effects you are going for, and some of them can be pretty cool, but once they are used, things like stalactites and blown transformers aren’t going to respawn on the map. Sure they can, but not if they are big, map altering pieces.