Levels 3 to 20
"RuneScape" players start at level 3 combat. Chickens and cows are very popular creatures for low level "RuneScape" players to kill. Chickens are essentially harmless, and it is practically impossible for players to be killed by one. Furthermore, they drop feathers which can be sold at the Grand Exchange for money. Cows also drop lucrative loot, such as cow hide. Both chickens and cows drop raw meat, which can be cooked and consumed to replenish health.
Levels 21 to 30
Players usually transition to killing barbarians at Barbarian Village or Minotaurs at the Stronghold of Security, found at the heart of Barbarian Village. Barbarians are very easily to kill as they have low health, but they inflict lots of damage, so players must be prepared to bring food. Minotaurs are a bit more difficult to kill than barbarians, but they drop lots of useful loot such as iron arrows and rune essences, both of which can be sold at the Grand Exchange. Iron arrows can be used for ranging when coupled with a bow. Increasing ranged levels can also increase combat level.
Levels 31 to 55
Hill giants and moss giants found at the Edgeville dungeon north of Barbarian Village and Varrock sewers respectively give lots of experience points and provide lots of lucrative loot, making them ideal targets for increasing combat levels. While both creatures attack at a very slow rate, they can inflict lots of damage, so bringing food is mandatory. However, the big bones and runes that they drop will easily make up the cost of the food.
Levels 56 to 75
The zombies and giant rats at the second level of the Stronghold of Security have a decent amount of health but have a very low defense rating, making them very easy to kill. Zombies also drop steel arrows, which can be sold at the Grand Exchange for money or used to increase ranged levels. Both creatures deal lots of damage, so players should definitely bring food. The area may also be crowded, so players may have to constantly shuffle between servers.
Levels 76 to 100
The flesh crawlers in the second level of the Stronghold of Security are aggressive to any player but deal very little damage and respawn incredibly fast. Players often exploit the pugnaciousness of flesh crawlers by leaving their characters while they go away from their keyboards. However, characters must leave and re-enter the second level periodically, as flesh crawlers stop attacking players after 10 minutes.