I would imagine that smoke grenades are one of the most misunderstood items for beginner players. They are the only way for a player to add obscurement and cover so they are important. Here are some of my thoughts on smoke.
Smoke grenades only cover the level on which they are placed. A smoke grenade that explodes on the ground will not protect the inside of the skyranger, for example. For that reason I'd recommend using a smoke grenade on the ground and another inside the skyranger at the start of a mission. Scouting through the cloud and using shooters from behind the cloud is very effective, so effective in fact that there's not much reason to sweep the map until the smoke clears.
Smoke genades do not seem to explode properly in outdoor terrain, giving only wispy smoke. They are best used inside bases, buildings, and spaceships. Fortunately, the perimeter of the skyranger seems to be considered indoors.
Smoke can also help in situations where your scout will inevitably be put into the firing line. The most common situation is when you enter a cross shaped small spaceship where you know the alien will be standing at the back. If the scout carries a primed smoke grenade he will be able to drop it without triggering reaction fire and end the turn. The smoke grenade will (hopefully) provide cover during the aliens movement.
I suspect that reaction shots are less likely against targets in smoke. For example, when a proximity grenade explodes there will be plenty of smoke so reaction shots against any following aliens can be lost. Perhaps someone else can verify this.
A few thoughts:
The smoke grenade on the Skyranger level only really works if you are intending to fly out the back or you want to prevent aliens that are within visible range (20 tiles) from spotting you. When you move onto the ramp, you're technically on ground level. Your unit is offset, but otherwise on ground level, and should take advantage of smoke in its tile.
Smoke works the same way as explosives - solid objects block the blast from going further, so you'd only get the smoke to go inside the Skyranger and out the back. Oh wait, do you mean they don't produce the same amount of smoke? This could be a fire/smoke particle limit problem.
Reactions are reduced because smoke reduces the observer's maximum visible range. You see, the defender can only react if it spots the attacker - and if it can't, then it won't. However, the moment you step into a portion of smoke that's thin enough to allow the defender to see you, the defender gets a chance to react given all the conditions are met (higher reaction level and sufficient TUs to react, etc).
My guess is the intent of a smoke grenade in the craft is to stop aliens firing into the craft. Usually this isn't something you need to defend against, but a well aimed stun bomb can incapacitate the majority of your team if they're still in there.
As for smoke density, there are actually multiple "thickness" levels that can appear in any one tile. This density changes as turns procede. I would assume denser smoke provides better cover then light smoke, but I've had some difficulty working out how to produce the different types. My map editer only displays one type of smoke, as I can't even work out how to tell them apart in the save files.
Smoke moves around the place, and can be guided by walls. My guess is if too much smoke gets directed into one tile, that smoke becomes dense. This won't happen out in the open, so you get light smoke.
As for reaction shots, unless the smoke completely obscures the unit in concern, there won't be any difference.
- Bomb Bloke 01:36, 14 September 2006 (PDT)
My limited experiments suggested that smoke grenades produce much denser smoke than other sources (visibility 4-6 squares at the center for the first few turns) but thins rapidly. As for
the defender gets a chance to react given all the conditions are met
one must keep in mind reaction fire triggers#mutual surprise: if you spot them at the same time as they spot you, they won't shoot until your next action, no matter what your respective Reactions are.--Ethereal Cereal 22:32, 18 September 2006 (PDT)
I suggested releasing a smoke grenade at the front of the skyranger on the first turn as grenades are cheap, it's no handicap to your soldiers, and it only has to save lives occasionally to be worthwhile. - Egor
- Definitely at the base of the ramp, and when I'm facing a high-risk setup (like the UFO door itself), I do another inside the Skyranger. But then you've used up almost all your smoke allotment for the next 20 turns, due to the game only allowing 400 "smoky" squares simultaneously. If smoke didn't need to be conserved due to this, I'd probably use 5-10 grenades per mission.--Ethereal Cereal 20:58, 23 September 2006 (PDT)
No offensive stun capability exists - rewrite needed.
I've never seen aliens stunned by smoke grenades. I've tried it "in combat" and I've tried in test setups. I've just retried it using Seb76's loader to play from the enemy position. The aliens take no stun from smoke grenades. Not when they stand in smoke, not when they move in smoke, and definitely not when someone fires an incendiary while they are in smoke.
I would suggest the section on stunning is rewritten to reflect that this is just a "friendly fire" hazard of using smoke, and aliens (perhaps unless mind controlled) are immune to stunning effects of smoke. Spike 09:49, 14 December 2008 (CST)
- Totally agree. I did numerous tests on this as well over at the StrategyCore forums and my results matched yours. The only time aliens can take stun damage from smoke is when they are under X-COM Mind Control. The incendiary trick doesn't work either for enemy units. Only friendlies (sans tanks of course) suffer. --Zombie 13:15, 14 December 2008 (CST)
- Rewrite done, thanks Zombie. I also updated Known Bugs. Spike 15:56, 14 December 2008 (CST)
- Are you sure? I could have sworn I've used smoke grenades as a poor man's stun bomb in the past by filling medium scouts with smoke and waiting them out. --Schwern 19:30, 31 May 2010 (EDT)
So... how much does 1 square of smoke obscure sight?
Need to run some tests on this... which will be confused by this whole thick smoke and thin smoke thing... but... I want to find out exactly HOW MUCH each tile of smoke obscures vision range... On a similiar note, I wonder how much Smoke obscures X-com vision at night? Is it possible to regain mutual surprise by surrounding an X-com agent in a pile of smoke? Or would really dense smoke reduce alien sight to 4-6 squares at night, but reduce vision for agents to 2-3 squares??? That would be bad! Jasonred 09:25, 18 March 2009 (EDT)
- Use my battlescape editor to work out how a given cloud of smoke effects vision. See SMOKREF.DAT for the formulas behind it. - Bomb Bloke 09:39, 18 March 2009 (EDT)
- Linky please... hahaha... yes, I know I'm being asked to be spoonfed, but I don't have any game editor at all at the moment... they were turning my "normal" X-com games into strange and unfamiliar creatures. Generally, I find that editors and itchy fingers and a curious mind make a very very disturbing mix, at times... - Jasonred
- Here's a link. - Bomb Bloke 19:37, 18 March 2009 (EDT)
Does smoke actually reduce the enemy's accuracy or provide a defense boost, or is its effect limited only to reducing the sight range and reaction shot chance of enemies? I looked at the SMOKEREF.DAT page but I'm not sure if I'm understanding it right. Anothrgamer1234 (talk) 15:03, 28 May 2020 (UTC)
- It doesn't affect any stats / percentages in the game. All smoke does is obscure the view. If you can't see the enemy or they can't see you, there'll be no reaction fire or shots during the enemy turn. Defense boost doesn't exist period other than equipping better armour, unless you count the environment/obstacles as "defense boost", which is really stretching that term. Accuracy depends on the accuracy stat & weapon modifier as well as your remaining health points (if lower than max) and what body part has fatal wounds. Bard (talk) 15:17, 28 May 2020 (UTC)