During our time of playing Dark Heresy a few house rules have cropped up into the game, some that has been with us since playing WFRP 1st edition (Technical Knock-out and Perfect Hits). I just thought I would share these thoughts, and see what you fellow players and gamemasters think of them.
Blessings of the Warp
When a psyker or sorcerer rolls a 10 on any of the dice rolled for power manifestation, he may choose to recieve the blessing of the warp -> gaining more power for greater risk. For each 10 rolled on the initial dice rolled (not additional dice from this rule) he may roll another 1d10 and add to the power manifestation roll. However this carries greater risk, and these "blessings" of the warp cause psychic phenomena on a roll of 7,8 or 9.
Technical Knock-out
Whenever a hit to the head occurs, there is a damage dealt x 5% risk that the character is knocked out for 1d10 minutes.
Perfect hit
No defense against damage is perfect as every armour has weak spots, and each person has vulnerable spots that can be hit with a lucky blow or shot. As a result any double roll (11, 22, 33, 44, etc.) on an attack roll that is a successful attack, ignore armour and toughness bonus for the purpose of dealing damage.
Crafting - Time
The crafting rules as written in The Inquisitors Handbook made little sense to me, in that it did not matter how well you rolled when it comes to reducing the time needed towards completing what you where trying to create, but when you fail it greatly increase the time needed to complete the work. As such the time needed is not only reduced by the time interval as described, but the Degree of Success on the roll is also deducted from the time needed.
Firing Squads - Group Fire
When a group of at least 5 characters is firing weapons at the same target or targets (count this as firing into an area with a radius of 5 meters), their weapons fire is treated as a single automatic fire attack. Make one roll with the average of the characters BS, and for each Degree of Success allocate one hit to a target in the firing zone. Damage caused are in this order; least powerful weapon, medium damage potential, maximum damage potential, and then over again. Roll hit location randomly. The maximum number of hits is equal to the number of characters participating in the firing squad. Automatic weapons gain no special bonus to the effect of causing more hits when using these group fire rules. ANd further facing fire from a firing squad causes Pinning just as Covering Fire does.