From Dofus

All items have a weight, measured in pods. You cannot carry more pods than your carrying capacity.

From The Vault

In Fallout 3, weight refers to the measure of how much an item weighs in pounds, and how many total pounds the player is carrying. Most items have a weight rating. The total weight the player is carrying is the sum of the weight ratings of all items carried, held, and worn. Carrying too much weight can affect a player's movement rate and movement abilities.

The Weight Limit (Carry Weight)

The amount of weight the player is carrying and the total weight limit (carry weight) is shown in the Pip-Boy along the top of the display while the ITEMS button is selected. The weight values show up as a fraction to the right of the Wg label, with the total amount of weight carried coming first, and the weight limit coming after the /.

The weight limit is not a hard-limit that prevents you from carrying more items. The weight limit is a threshold that if surpassed, limits player movement until the weight carried matches or drops below the threshold. Being exactly at the weight limit will not affect player movement; the player is only penalized for going over the limit.

Weight And Movement

If a player is over the weight limit, their movement is limited to walking speed and the player is unable to jump. Normal walking speed is not reduced for a player over the limit, so toggling the movement rate from run to walk has no noticeable effect.

Players over the weight limit also cannot use the fast travel feature, but being over the limit does not affect sneaking, combat, or any other normal gameplay functionality.

Managing Weight

Most items have a weight rating listed in their description. Any item with a weight rating of - - has no weight, and therefore may be carried in any quantity without concern that it will contribute to the player being over the weight limit. Most ammunition, quest items, and chems have no weight rating.

The game moves very slow if you are over the weight limit, so staying under it is of top concern. Here are some tips for staying under the limit:

Store It!

Use the many storage options in your house at Megaton or Tenpenny Tower to store items you wish to save for later in the game so you don't have to lug them around. If you don't yet have a house, explore the map to find a container such as a locker, box, or Nuka Cola machine to use for temporary storage until you get your house. There is also a Mailbox in Springvale that is near the spawn point, and can hold an infinite amount of storage goods, is able to be "decorated", and doesn't have the multiple load screens like the two houses you can own.

Plan It!

Plan your inventory before setting out. Travel light and take only what you expect to normally use. Check your total item weight before leaving for some action and become familiar with how much you normally carry, so that if you are over your normal rating you are alerted to the possibility you are carrying something you don't need. Consider these tips:

• Minor healing items such as food and animal meat are plentiful enough during most encounters; supply yourself with only healing items that have no weight rating and expect to supplement them with items you find in the field.
• Unless you are an explosives fool, only carry a few grenades and mines; the times you actually need them are rare, and there are plenty to pick up in many encounters.

Drop It!

It is better for your sanity and game enjoyment to drop heavy items to ensure fast movement rather than poke along at a snail's pace. Here are some tips on how to drop items efficiently:

• Upon zoning into a new area, look for a container near the entrance that you can use to store bulky items you don't want to lose. Items stored in a container will usually remain there unmolested so you can return later and re-acquire them. When you've cleared the place out, it will be easy to grab a handful of stuff, zone out and fast travel to a merchant to sell it, then repeat until you've got it all.
• Some items are worth very little yet have a lot of weight, such as fission batteries, or heavily damaged big guns or armor; consider dropping them even if you may not be able to retrieve them later.
• If you plan on traveling by foot and not using fast travel, Dropping an object and pressing 'Z' on PC or clicking right thumbstick / analog stick down on the 360 / PS3 will allow you carry the object without it being in your inventory. While this allows you to move at full speed if you would otherwise be over the weight limit, it effectively prevents you from engaging in combat by keeping the object directly in front of the player, blocking any bullets or other attacks.

Note: Items dropped on the ground in the Capital Wasteland have a chance of being picked up by NPCs while you're away.

Sell It!

If you have no reasonable way to store items for later pickup while out in the field, and you don't want to drop things, fast travel to merchants to dump inventory. If you're in the Capital Wasteland, move near a discovered location on the world map and make note of your position before you leave so you can return to the same spot. If you're in a zoned area, about the time you get full, find the nearest exit to the Capital Wasteland and do the same. Remember you can pop out to balconies or rooftops and still fast travel -- you don't always have to go out the way you came in.

Merchants have limited funds to pay for the items you are selling, and some are not available at certain times of the day. Underworld, Big Town, Megaton (Gob and Doc Church), and the traveling merchants are good resources for late-night sell-fests. Sell the heavier items first in case the merchant doesn't have enough to pay for everything you want to sell.

Repair It!

The game rewards a high repair skill. Encounter areas often have multiple enemies that are similar in kind, and which will carry similar weapons. When you reach the weight limit in the field, boost your repair skill to its max with clothing or drugs and repair items using other similar items. With a decent repair skill, you may find yourself transitioning from 3 sets of Raider Painspike Armor worth an average of 20 caps each and weighing a total of 45 pounds, to a single set of Painspike worth 100 caps and weighing 15 pounds.

Boost It!

Ant Nectar, any alcohol, and Buffout all raise your strength skill for a limited amount of time. You can use these drugs to temporarily increase the amount you can carry and maintain a fast movement rate. Fortunately, if you are under the effects of these drugs, you can still fast travel even if the effect would have worn off during normal travel of that distance. In that case, the effects will wear off once you emerge from fast travel mode.

The various types of Power Armor also boost your strength and increase carrying capacity, but require special training to use.

From Final Fantasy Wiki

Weight is a common status ailment in Final Fantasy XI. There are a number of enemy abilities that can impose this ailment. Players can also impose this on their enemies by casting the Red Mage spell Gravity.

Weight will reduce the land speed of a character and also lower his evasion characteristic. This will make it harder for the effected target to avoid attacks and also almost impossible for it to run away or catch up to a target. For this reason, it is very useful in the strategy known as kiting.

From the RuneScape Wiki, the wiki for all things RuneScape

Carrying less weight allows players to run for a longer period of time.

The Weight of items in RuneScape refers to how heavy they are, and is measured in kilograms (kg). Every item has a weight, although it may be zero (for example, stackable items) or even negative, such as the boots of lightness.

Players can see the total weight of the items they are carrying on the Equipment Stats screen from the Worn Equipment interface. This will include items they have equipped as well as those carried in the inventory. Many nonstackable items weigh fractions of a kilogram, but the Equipment Stats screen truncates (does not show the decimal portion), so these may appear as zero even though they have some slight weight.

Effects of weight

Carrying less weight causes energy to decrease slowly, and a higher Agility level will cause energy to recover at a higher rate. Players who undertake activities requiring a lot of running around would be well advised to minimize the total weight they carry whilst doing so, since they will be able to run for longer. However, having negative weight has the same effect as having 0kg weight.

Some activities in RuneScape require players to weigh no more/no less than a certain amount. For example, whilst doing the Pirate Pete part of the Recipe for Disaster quest, players must be carrying no more than 27 kg to dive off Port Khazard. In the quest Temple of Ikov, players must weigh less than 0kg to cross a bridge, this is just after having received the boots of lightness. Also, in order to use the Balloon transport system, players must be carrying less than 40 kg. To get into Movario's base (during and after While Guthix Sleeps) you need to weigh more than 1 kg.

Weight limits

The heaviest items in RuneScape are Barrels of naphtha, each weighing 36 kg. Filling an entire inventory up with this item increases the total inventory weight to 1,008 kg.

The lowest weight that any player in Runescape can have is –38.0 kg. To obtain this weight, the following items need to be equipped: Agile top -12kg, Agile legs -10kg, Boots of lightness -4.5kg, Spottier cape -4.5kg, and Penance gloves -7.0kg.

Heaviest weight

Slot	Image	Item	Weight (kg)
Headwear		Gold helmet	31
Cape		Diving apparatus	10
Neckwear		Seal of Passage	4.5
Ammunition		-
Weapon		Barrelchest anchor	30
Body		Granite body	22
Shield		-
Legwear		Granite legs	15
Hand		Rock-shell gloves	2.5
Footwear		Bandos boots	6
Ring		-
Inventory		28 × Barrel of naphtha	1,008
Total weight			1,130

Note: The Barrelchest anchor can be substituted with the Stone of Power from the Fist of Guthix minigame. The Barrelchest anchor is a 2-handed weapon, therefore the Shield slot will be empty.

Heaviest weight (free player)

Slot	Image	Item	Weight (kg)
Headwear		Adamant full helm	2.7
Cape		Any non-team cape	1
Neckwear
Ammunition		-
Weapon		Adamant battleaxe	3
Body		Adamant platebody	11
Shield		Adamant berserker shield	7
Legwear		Adamant platelegs	10
Hand		Green dragonhide vambraces	1
Footwear		Leather boots	3
Ring		-
Inventory		28 × Adamant platebody	308
Total weight			352.7

Lightest weight (members)

Slot	Image	Item	Weight (kg)
Footwear		Boots of lightness	–4.5
Hand		Penance gloves	–7
Cape		Spottier cape	–4.5
Legs		Agile legs	–10
Body		Agile top	–12
Total weight			–38.0

Note: The lightest weight free players can achieve is 0kg; simply by wearing and carrying nothing.

Trivia

• In the real world, the kilogram is a unit of mass, not weight. The mass of an object is always the same; the weight depends on the gravity.
• Processing many items increases or decreases their weight when their weight should do the opposite, for example: an inventory of 14 bowstrings and 14 yew longbows (u) weigh 7 kg more than their combined product of 14 yew longbows, and a steel platebody weighs less than the five steel bars used to make it. As for the steel platebody, this could be because some of the extra steel was scrapped during the forging process.
• Sometimes RuneScape item weights are unrealistic - for example, the cannonball, which is stackable, weighs 0kg, when one would expect it to be quite heavy. This is presumably so that the Dwarf multicannon is easier to use. There is also another rather amusing factor - no matter how many Coins you carry in your inventory - which is very many - you can never increase your weight, which will stay the same. However, this could be due to the very inherent magical nature of Gielinor itself.
• There once was a glitch that activated weight-lowering items without having to wear them. A player could have a full inventory of spottier capes and weigh about –126 kg. The glitch is now fixed.