Talk:Proximity Grenade

Proximity Grenades Vs. Zombies

To be blunt, this is an absolutely horrid idea. One, if you have enough TUs to mine the Zombie in(75% TUs from TWO soldiers), you really should just shoot the thing, because with that many TUs you should be able to kill it and the resulting spawn.(Same for any alien, really, unless its early in the game and you've only got peashooters for weaponry). In addition, because the first Proximity Grenade will destroy the second one, what happens if you kill a Zombie with Proximity Grenades is that you spawn an enemy Chryssalid with FULL TUs...DURING the Alien turn. This can only be described as a tactical nightmare! Again, though, this tactic could work reasonably well in TFTD(barring the objection about TUs). Arrow Quivershaft 11:06, 16 May 2008 (PDT)

Grenade limits

The game keeps the list of armed prox. grenades in a separate array (possibly for performance reasons). The maximum number of elements in this array is 20, limiting the number of armed grenades to this very number. When you reach the limit, no particular message is shown to say so (the 'grenade activated !' message is even shown, and the quantity1 field is set to 1 too). The grenade however will never detonate. I didn't check if loading a savegame repopulate the list, but if not this is most likely the reason why the armed status is lost when loading a game. Seb76 16:48, 18 May 2008 (PDT)

From a practical perspective, 20 Proximity Grenades is probably plenty. Given that X-COM can only haul 80 items to the drop site, in order to fill up the array, you'd need to have over 1/4th of your item stock be Prox. Grenades, and I somehow think most people will consider that somewhat impractical/overkill. Still, good to know for reference. Arrow Quivershaft 16:52, 18 May 2008 (PDT)

Yeah, it is only for informational purpose. I stumbled across this limitation and thought it might explain the loss of armed state bug. Also it is a limitation on _armed_ grenades so you can bring more, it won't be a problem. I don't see how you could toss that much grenades in one turn and not having any one alien blow itself up with one of it to make more room anyway ;) Seb76 17:04, 18 May 2008 (PDT)

Kinda the point, yeah. In order to encounter the bug, you'd need to deploy 21 armed mines and hope that none were detonated. Or, conversely, have deployed a number of mines equal to 21+detonated mines. I'll add this to Known Bugs. Arrow Quivershaft 17:06, 18 May 2008 (PDT)

You may want to do some tests first then, I did not do any here so for now this is 'pure' speculation ;) Seb76 17:09, 18 May 2008 (PDT)

Ooops, thought you'd done the tests. Oh well, I'll do tests after finals and see what I can come up with. Sorry. Arrow Quivershaft 17:14, 18 May 2008 (PDT)

Hehe, I usually 'read' through the code and deduce behaviour. I'm often too lazy to check ^^. I did test the hot grenades patch however Seb76 17:17, 18 May 2008 (PDT)

What's this "hot grenades patch"? I'm trying to collect all the available bugfixes... Phasma Felis 16:08, 1 June 2008 (PDT)

Also from the look of it, only grenades which detonate from proximity contact will free the entry. If they are destroyed with another explosion, they won't and they will pollute the array. Seb76 17:25, 18 May 2008 (PDT)

The game maintains (actually, I'd say half-maintains since it is a real bug nest...) a list of references to obpos.dat entries for armed prox-mines. When you arm a prox mine, a new entry is added in the list. Each time a unit moves one square, the list is parsed and if the unit is too close to one obpos, it explodes and the entry is removed from the list (Note that no check is performed to test whether the obpos entry in question is a prox-mine or not...). So far so good. However, the developers must have implemented this at the end and not really tested it because it has the following flaws: the list is _never_ initialized at the start of a tactical mission (actually the OS sets it to 0 at process startup but that's another point) so the next mission will still have the list set from the previous mission (with the know "exploding" consequences). A second issue is that an entry is removed from the list only when detonating from proximity contact, so prox-mines destroyed by other explosions are not cleared from the list. Finally, the list is not saved nor recreated when a savegame is made/reloaded (this explains the inactive mines when you reload a game). Since the games uses the 'quantity1' offset to indicate whether a prox-mine has been armed or not, this also explains why when you save/restart/reload a mission, the prox-mine is still not activable (the quantity1 is still set to 1). I don't know if it understandable english, but it's quite late now so I'll leave it as-is... Seb76 17:23, 2 June 2008 (PDT)

Pinning an alien

Guys, I'm pretty sure the bit about "pinning" aliens with a grenade on either side is pointless, since you can do the same thing with one grenade in the alien's square. Am I missing something? Phasma Felis 16:08, 1 June 2008 (PDT)

I agree it's pointless, but I'm trying to convince others of that as well. Similarly, debate is good. Saying "No" comes off as overlording, whereas saying, "I don't think so, because..." is more friendly. Hot Grenades is a patch made by Seb76 that modifies grenades so they detonate regardless of whether they're held in the inventory of a unit. The patch-code is here, and a downloadable program is at the bottom of this page. Arrow Quivershaft 16:44, 1 June 2008 (PDT)

I may not have been clear :) Whether "pinning" is useful or not as a tactic is a matter for debate, certainly, but I'm pretty sure it's a matter of fact that using two grenades will not have any better effect than one in this case. Phasma Felis 16:54, 2 June 2008 (PDT)

But wouldn't that be in all cases, not just this one? As mentioned below, I think we're all pretty sure aliens ignore Proxies, so one to the side of the alien won't alter its AI to your liking. And two to the sides will also have the same effect as one on its square; if it moves, a proxy goes off. Can a "direct hit" with a proxy be achieved if the alien walks right onto the grenade? In that case, the only added bonus I could see multiple proxies getting is a higher chance of said direct hit. It may not be conclusive evidence, but if aliens saw proximity grenades, they would in all likelihood walk around them whenever possible. On the "farm" level, a proxy on the corner of a building (with ample open space around said building) will almost guaranteed detonate on any alien maneuvering around said corner, as basically whenever I plant those, it either goes off, or I don't get attacked from that area (not that I usually get attacked from there after an alien dies on it anyway). I think the main question here is... what extra effect does one go for when they try to "pin" an alien with proximity grenades ? I suspect there are none whatsoever. NightChime 18:30, 15 January 2009 (CST)

To correct a mis-throw that fell one tile short? -NKF 23:49, 15 January 2009 (CST)

I would see that. But I also wouldn't call that "pinning"; that's just a re-throw, even if you choose to throw it on the other side of the alien, unless you do so for whatever advantage pinning might bring. I think we just need to raise our collective Imagination to find said advantage. NightChime 19:45, 20 January 2009 (CST)

Heh, I'm not really for multiple mines myself. The only desired effect of pinning or tossing a mine on the other side (due to a misthrow) is to ensure that the alien will set off the explosive at the end of the turn. A one-tile short throw would leave the alien open to walk away from it - even if it doesn't realise it. You could say the whole matter is really more a case of "penning" rather than "pinning". -NKF 23:20, 20 January 2009 (CST)

Of course it won't. The first Prox Grenade will destroy the second; that was noted in my first post at the top of this talk page. ;) Arrow Quivershaft 19:21, 2 June 2008 (PDT)

Would two mines really prevent them from moving? I mean the AI's not that smart and will happily move its own unit into the triggering tiles around an armed mine.

Using two mines would be wasteful as one would destroy the other. The triggered status of the armed mine apparently sticks around and gets passed onto whatever object that ends up in the slot previously occupied by the mine. In the one executable version of CE it will even carry over to the next mission (unless you exit the game). It's not so bad if it just happens to be the odd corpse that goes pop (or worse, a stunned soldier). However when dangerous objects like large rockets or high explosives just happen to inherit the armed flag, just hope that it's not you that triggers it. -NKF 03:01, 2 June 2008 (PDT)

The one place where I can see "pinning" as useful is against Chryssalids or Zombies; if you don't have enough firepower to reliably take them out, you might have enough TUs to drop a prox at their feet and kill them in subsequent turn. However, will a Zombie or Chryssalid actually stand still when on top of a prox? If so, it might come in handy, especially early-game.--Ethereal Cereal 20:01, 2 June 2008 (PDT)

I really doubt that the AI pays any heed to Proximity Grenades. On the rare event I use one, it doesn't even flinch at it. If the AI paid heed to them, it's entirely possible that throwing one outside the door of the UFO would lock all the aliens into the UFO since none of them would want to step on the mine. Also note that deploying a proximity grenade takes 75% max TUs, at minimum. 50% to prime, 25% to throw. You could get off 2 auto bursts with most weapons in that time, and unless your accuracy is absolutely HORRID you should be able to kill most aliens at medium range, provided you have a weapon with appropriate stopping power versus the beastie. Arrow Quivershaft 20:05, 2 June 2008 (PDT)

Eh, I should have figured, the AI indeed does not pay attention to Proximity Grenades. (Just tested it: at their feet, on two sides, makes no difference.) So all talk of "pinning aliens" is complete bunk. Oh well, it would have been fun playing "taunt the Chryssalid". :-) --Ethereal Cereal 23:19, 2 June 2008 (PDT)

Experience from proximity grenades?

I've heard that triggering proximity grenades gives the unit that does it hits which make the unit get experience at the end of the mission. I was wondering if the exp is just for triggering it or if it gives the units hits equal to the number of units in its blast radius (does itself count?) so having 11 friendly or enemy units in the blast radius would give it 11 hits (unless I'm interpreting this wrongly or if friendly fire this way doesn't give hits.)? PocketUFOPlayer? (talk) 09:58, 15 March 2019 (CET)

To my understanding, all grenades give Firing Accuracy experience equal to the number of enemies hit. The trick here is that grenades have an "ownership" flag which tells the game who gets the experience, and the flag doesn't always behave intuitively. Specifically, dropping a grenade doesn't reset the flag (so the experience goes to the last person who threw the grenade, or to the first unit if nobody threw it), and triggering a proximity grenade does. So if you set off a proximity grenade with your own soldier, he'd get Firing Accuracy experience equal to the number of enemies (non-MCed aliens and MCed X-Com troops) hit by the blast. I'm not really sure whether a soldier under alien mind control setting off a proximity grenade would get Firing Accuracy experience for blowing himself up (as he is currently an enemy) - it'd depend on whether XP checks what side someone's currently on.

Note that none of this applies to Throwing Accuracy experience. Throwing objects always awards 1 Throwing Accuracy experience to the thrower, and Proximity Grenades are no exception. Magic9mushroom (talk) 04:06, 16 March 2019 (CET)

Standing on the edge

In the tips section it says "PGs detect movement into, but not out of, the eight surrounding squares, meaning you can walk away from a mis-throw." and in the proceed with caution "A grenade will not detonate when a unit moves into its detection radius vertically". Does this mean that you cannot walk onto the mine if already in the 8 squares. If the middle square is also one of the squares that detonates it then I think it should be mentioned as well as moving down into the blast radius and then moving normally onto the mines tile. PocketUFOPlayer? (talk) 10:11, 15 March 2019 (CET)