Unconscious

To knock any unit unconscious, its stun damage (grey inner bar) has to exceed its health (red outer bar). Thus a shortcut to unconsciousness is to have friends lightly wound the unit to reduce its health (eg with a few pistol rounds) before or after hitting it with your stun weapon. Tricky but it can save your life.

Stun damage weapons

• The Stun Rod, a highly accurate hand-to-hand combat weapon, although few soldiers will gladly accept the chance to poke a dangerous alien with a stick. And large large aliens require quite a few pokes to knock out! (Mutons take 2-6.)
• Smoke inhalation, approx. 2 points/round, e.g. from a Smoke Grenade. Does not affect sealed Power Armor or robots.
• The Small Launcher, which fires area-effect Stun Bombs.
• The Thermal Tazer melee weapon with freezing effect (TFTD).

Recovery

Stun damage fades slowly, approx. 5 points/round. Medi-Kit stimulants will counteract stun damage on application. To revive an unconscious unit, stand on the square where their body is lying and use the medikit until it can't find a target. The revived unit will be standing nearby without any equipment. They will have full TUs.

Note that with aliens (and soldiers?), the medikit will not give the "no one there" error once you have revived the alien. In other words, you need to visually check after each stimulant is applied to see whether the alien has awakened. If not, you may needlessly use up TUs and stimulants even though the alien is already awake. If terrain blocks the view of the soldier's feet so that you can't see if the alien is still there, use their inventory. Also note that the soldier who revives the alien will not see the revived alien, even if it's standing right in front of them. You must select some other soldier who can see that area, or select some other soldier and then come back to the soldier with the medkit. (The battlescape is not updated for the medkit soldier - another soldier must be selected to force an update.) This is why, when applying stimulants, you need to keep checking that the unconscious alien is still there (unconscious) - you won't see them once they revive unless you force an update.

Units that wake up cannot wake up on the same tile as the person applying the medication. Instead they will often wake up one tile to the north. If that space is occupied then the unit will attempt to appear in the next tile in a clockwise direction until a free location is encountered.

Units can be picked up and/or stored in a soldier's inventory. This won't aid or affect them; they will still wake up with the same conditions. Curiously enough, if the unit holding the unconcious body is flying in the air, the stunned unit will wake up and stand in mid-air. This unit will stay up in mid air until given a move order. This bug cannot be exploited to set up floating snipers as equipment cannot be passed to the unit.

One word of caution: If the unconcious unit is an alien and it has a melee attack, like the Chryssalid (UFO) or the Lobsterman (TFTD), it will be in a perfect position to attack you if you've been carrying it and it wakes up.

One additional word of caution: Be very aware of a bug with unconcious units in your unit's hand slots. If they wake up they will no longer physically exist in your soldier's hands, but on the battlescape display, it will look like they're still in their hands. As with other potentially buggy situations, do not click on the 'ghost' in your soldier's hands (to bring up the attack/throw menu). This will crash the game. Go into the soldier's inventory and place an item in their hand. This will clear the error.

Unconscious Aliens

• Can be identified by type and rank when picked up (move a soldier to the same square, switch to inventory screen).
• Could still wake up, but will not pick up weapons. Aliens with melee attacks or built in weapons will continue to use them where possible.
• Can be made unconscious if already half-stunned, by a small amount of damage that knocks their health below the stun level. Pistols suggested.
• Will never have fatal wounds UNLESS you were mind-controlling them when they were wounded. (Only friendlies get fatal wounds, not aliens - but an MC'd alien counts as a friendly while under MC.)
• Attract other roaming aliens. Can be used as ambush bait e.g. if boxed into the Skyranger [Xeno].
• Unconcious bodies of any type will die instantly when hit by explosives - regardless of how resistant they are or how strong their armour is. Also, you will not get missions points for aliens killed while unconscious. So only do this if desparate to kill them (but also see next bullet).
• Large (four square) aliens NEVER wake up from unconsciousness. Ever. Occasionally a quarter of the unit may not fall unconscious. It's rare, but has been known to happen.

Unconscious Soldiers

• can be revived by Medikit Stimulant (rate TBD)
• continue to suffer from fatal wounds (so check them a.s.a.p. if they've been downed by shots or explosions - but stun bombs will not cause wounds)
• do recover on their own
• can be carried or thrown like objects
• can be thrown up or into inaccessible areas, see Grenades
• if killed by an explosion, do not count toward end-game tally. Applies to both soldiers and aliens.

Knocking a unit unconscious actually replaces it in the game with an "unconscious unit type item". Associated bugs include cloning a soldier where one clone awakens as the other dies, and extinguishing a soldier on fire by knocking him out.