D&D House Rule: Cloaks & Backpacks

 "A cloak slows you down in a fight." - Bronn ('Game of Thrones' TV series)

  While playing a swashbuckling, lightly-armored character in one campaign, I was often annoyed at the idea of imagining my dexterous character burdened with a backpack.
  I imagined that if someone was expecting a fight, they'd make sure to remove their backpack before entering a dungeon, or going into a battlefield. In real life, having a backpack on can be a serious issue when it comes to being grabbed from behind, as it's easy for someone to pull you backwards and then to the ground.
  But when it comes to D&D, as long as the contents of the backpack don't give you any extra encumbrance, you're good to go! There's just no practical reason not to wear a backpack during a fight, despite all the logical reasons one could think of in real life. The same goes for cloaks.

  So here are some house rules to implement such logic into D&D. While I can't speak for every single variant and edition of it that exists, I'm confident they can work well with pretty much all of them.

  Backpacks

  - If a character is tripped while wearing a backpack, the DM must roll 1d4. On a roll of 1, the character fell on top of his backpack. The DM must roll 1d4 again, representing the damage the contents of the backpack take due to the fall. The damage can be to a single object, or distributed, as decided by the DM, either randomly or by logic.
  Should a character actually fall from a high place instead of being tripped (or due to a trip!), the DM must roll the first 1d4 as before to see if the character falls on his backpack. If it comes up on a 1, the character and the backpack take the same falling damage. That said, if the backpack contained objects that could possibly soften a fall (A pillow, bed sheets, etc) then the DM could remove 1-3 HP of damage from the total falling damage.

  - Anyone trying to grab/grapple the character from behind gets a +2 to their roll if they choose to grab the backpack. If the backpack is full, make it a +3.
  If the attacker rolls a natural 20 or exceeds the required number on his roll by 5 or more, he has managed to really entangle the character in his own backpack. The defender is at -2 to get out of the grapple, and getting out of it means he'll have to leave his backpack in the hands of the attacker. (Which might sometimes be what the attacker wanted.) Optionally, a character could use a small cutting weapon to cut himself free of his own backpack in 1d3 rounds. This will, again, leave the backpack in the hands of the attacker.
  Anyone who has successfully grappled someone by their backpack also gets a +2 to any roll made to trip them to the ground. However, if the attacker wants to continue the grapple after such a trip, he must follow the backpack-wearer to the ground and also become prone to others.

Cloaks

  -  Anyone trying to grab/grapple the character gets a +1 to their roll if they choose to grab the cloak.
   If the attacker rolls a natural 20 or exceeds the required number on his roll by 5 or more, he has managed to really entangle the character in his own cloak. The defender is at -2 to get out of the grapple, and getting out of it means he'll have to leave his cloak in the hands of the attacker. (Which might sometimes be what the attacker wanted in the case of fancy or magical cloaks.) Optionally, a character could use a small cutting weapon to cut himself free of his own cloak in 1d3 rounds. This will, again, leave the cloak in the hands of the attacker.

  - Anyone pulling a medium or bigger weapon from under a cloak gets a -1 penalty on their first attack, since when worn a cloak will usually cover one's arms. After that first attack, the cloak can be considered out of the way unless the character rolled a natural 1, in which case the penalty remains for another round as the cloak is still in the way.
  A character can pull his cloak back over their shoulders ahead of time if they expect trouble to avoid this. (Or they can pull their weapon ahead of time, but sometimes outright drawing a weapon can make the difference between a possible fight and an unavoidable fight.)

  - Anyone wearing a cloak over their arms and shoulders gets a bonus to protect themselves from the rain and cold. The bonus will depend on the quality of the cloak. A good cloak will also protect carried objects from the rain.

  - Depending of the color of the cloak, a character could get either a bonus or a penalty on a hiding roll depending on the environment they find themselves in,  up to the DM's discretion.