Searching Corpses

Overview

Usually corpses using this concept have to be interacted with by using an action button (varies from game to game). Most games use this concept for realism; as in real life, if you killed someone, their money and ammo wouldn't come flying out, you'd have to check them for it. Sometimes an inventory is used along with this concept, allowing the user to decide what to pick up or leave on the corpse. Often a pattern emerges in games of this type where early on in the game, players will typically loot everything they can; while later on in the game they will become more selective and choose items based on potential re-sale value or if they plan on possibly using the items or swapping items later. But for those that love to collect everything, this concept usually entails mashing on the action button on a pile of fresh corpses. As is common in more games with an inventory system, there may be some kind of limiting factor on the amount of loot a player can carry on themselves at any given time (finite amount of space in a grid system, a maximum weight the player may carry). In this situation, a player may perform a quick cost/benefit analysis to decide what to leave on the corpse.
 
Sometimes the corpse remains until it is looted, and then disappears when empty.  In other games the corpse disappears and leave an icon such as a bag indicating the dead enemy has items to loot.  Due to the constant looting typically done in most MMOs, it is common to include the option to "Autoloot". This will loot all available equipment on the corpse without the user clicking on each individual one.
 

Objects Obtainable

Many kinds of very useful objects can be gained for a player by looting dead bodies. The types of loot will depend on what kind of RPG the game is. To provide some examples, in Oblivion, a more medieval type of story, some loot may be a longsword, mace, shield, or metal or leather armor. However, in a more modern or post-apocalyptic RPG, such as Fallout 3 or Borderlands, the components of a "drop" may consist of new guns, parts for a better gun, or more ammunition. 
 

Benefits of "Looting"

Other than providing you with snazzy new equipment, looting can also help you to better your character. Alongside the obvious gains of stronger armor or weapons, you can also improve secondary abilities you may have. For example, in Borderlands, you can gain new enhancements which will improve your special ability depending on what class you are and what your special ability is. Also, you can obviously sell the loot and make money off of it. 
 

Downsides

Right now, you may be thinking to yourself, "How can getting better equipment have a downside?" Right? Well in the latest Bethesda made games Oblivion and Fallout 3, if someone sees you looting a body, they will either attack you or report you to the guards. So remember, next time you go to loot a body, make sure you don't have any witnesses, just in case.