Prone: While in prone position you can only move your half movement speed.

Hit the Deck: Half action, go into prone position. You may couple a dodge reaction with Hit the Deck for no additonal action cost. (you can dodge and go prone at the same time)

I have a question also. Did headshots deal 2x damage in older editions of 40k rpgs? I thought it did in Dark Heresy but I don't see anything in Only War about it. Is that rule recommended? I feel like taking a shot to the head should have a little more gravity.

Sencho said:

One point then equals two? Two points then equals four? Seven points then equals fourteen?
Is the Damage to be doubled before or after Cover and Personal AP?

The game is deadly enough.

Headhots have never done double damage in any 40kRPG.

what were the rules about prone movement before? you rule sounds pertty logical.

as for headshots; game is defintely deadly enough haha

the dodge + hit the deck is also cool, perhaps only for people trained in dodge to reflect better training?

Our house rule is if it's a headshot, then the target makes a Toughness roll (difficulty GM's discretion depending on weapon) or get knocked out (or stunned at GM's discretion depending on weapon and/or head armor). The roll is required even if damage doesn't penetrate.

Gives additional incentive for players to have their characters wear helmets and provide more variation by adding additional protective qualities to some helmets. I.E. The standard Cadian-pattern helmet has "excellent" protective properties against shrapnel, but not concussive effects. The OLD helmets did , but the Mechanicus doesn't know how to make those anymore. You know, that "Dark Age of Technology" thing.

How do you dodge with hit the deck? You dodge as a reaction to your opponents on their turns, not on your own turn.

Our house rule is if it's a headshot, then the target makes a Toughness roll (difficulty GM's discretion depending on weapon) or get knocked out (or stunned at GM's discretion depending on weapon and/or head armor). The roll is required even if damage doesn't penetrate.

Gives additional incentive for players to have their characters wear helmets and provide more variation by adding additional protective qualities to some helmets. I.E. The standard Cadian-pattern helmet has "excellent" protective properties against shrapnel, but not concussive effects. The OLD helmets did , but the Mechanicus doesn't know how to make those anymore. You know, that "Dark Age of Technology" thing.

Did you also incorporate the extras from Deathwatch, maybe? I kind of like how Space Marines can get the Command bonus for their SMsanshelmetitus, an otherwise often simply fatal disease many ranking Space Marines seem to suffer from. While I can understand wanting to get your players to more often wear their helmets, it might just be better to persuade them to keep their heads down, and use cover. Many of the ranking dudes in the TT IG, even the ones who don't have names, often seem to doff their helmets, in favor of keeping their senses sharp, and inspiring the troops around them. If I flip through stuff, Sergeants are helmetless, CCs wear hats or nothing, Creed and Kell, Al'rahem, Lt. Mira (in Space Marine game), and other leaders are without helmets, and I'm not sure if the concept of "helmet" has even made its way to Catachan, yet.

Please note, I'm not trying to belabor the point, much, but there is a precedent for skipping the helmet; Space Marines are more inspiring, and Guardsmen probably see it as not that much more armor than their head naturally has.

So, since I brought it up, DW: Rites of Battle, p.152 goes into stuff for the perks of a Space Marine suffering from Sanshelmetitus. I'm not going to type the whole thing, but one thing is a +5 to Fellowship-based tests. Would this be appropriate to Only War games? Or is this setting not in need? I suppose they lose a bit less, but they also take a lot less to die.

Or as an alternative option for helmets and deadly headshots:

Helmets give full AP protection against all damage, Even if shots would realistically hit an unprotected part, such as lower face om most IG pattern helmets. Wearing helmets does however make the wearer subject to the "Anonymous Nobody" rule.

Anonymous Nobody characters under this effect cannot spend or burn Fate Points. They are the average troops who live and die by the normal rules of mortals.

Now people are motivated to take off their helmets when it is HERO TIME , and headshots have gotten deadlier.

A perception increase might be appropriate, as well. If nothing else, a standard guard issue helmet should penalise your hearing (since unlike marines it's not laced with autosenses).

As to extra effects for headshots... I see the argument, but no, there is no specific bonus for headshots - other than that the 'lethal' criticals come a lot earlier for the head location than say, the leg.

Headshots are only more lethal than a anything-other shot if they actually hit something important, and shots until you hit Crits are generally assumed to be grazing anyway, so I don't see the point. It clipped your ear, grazed your scalp, whatever. "Hit head" does not mean "shot in brain" or "hit in face," in just means that lumpy thing on top of your neck. Or the neck itself. Hell you can get shot right through the neck if it doesn't hit the trachea or an artery and not keel over.

The nastier Crits are bad enough.