Borderlands is a first-person shooter that includes character-building elements found in role playing games, leading to Gearbox calling the game a “role-playing shooter”.
At the start of the game, players select one of four characters, each with a unique special skill and with proficiencies with certain weapons. The four characters are: Soldier, Hunter, Siren, and Berserker. From then on, players take on quests assigned through non-player characters or from bounty boards, each typically rewarding the player with experience points and a reward item. Players also earn experience by killing foes and completing in-game challenges (such as getting a certain number of kills using a specific type of weapon). As they gain levels from experience growth, players can then allocate skill points into a skill tree that features three distinct specializations of the base character; for example, a Hunter can become specialized in sniping, gunslinging with revolvers, or going rogue and using his pet bird Bloodwing to assist in kills and gathering. Players can distribute points among any of the specializations, and can also spend a small amount of in-game money to redistribute their skill points.
Players start the game with the ability to use two weapons, but later gain up to four weapon slots, as well as slots for an energy shield, a grenade modification, and a class modification. Items collected but not used can be sold back at vendors for money that then can be used to buy better items. One of the key features of Borderlands is the randomly-generated weapons and items created either as dropped by foes, found in storage chests about the game, sold at vendors in the game, or as quest reward items. The game uses a “Procedural Content Creation System” to create these weapons and items, which can alter their firepower, rate of fire, and accuracy, add in elemental effects such as a chance to set foes on fire, and at rare times other special bonuses such as regenerating the player’s ammo. A color-coded scale is used to indicate the rarity of the weapon or item. It is estimated that the random system can generate over 17 million variations of weapons
When in combat, the player can take damage if their shield is depleted, affecting their health. If they lose all their health, they must either wait to be revived by another player or attempt to kill an enemy to achieve a “second wind”, or otherwise will be regenerated back at the last “New-U” station that they passed, losing a small percentage of their money in the process. Players eventually gain access to two-passenger vehicles, and can engage in vehicle combat with other enemies. Eventually, a system of fast transit points between the game world is available to the player; until then, players must walk or drive between areas to get around.
The game can be played alone, up to two players playing cooperatively through split-screen modes on the console versions, and up to four players playing cooperatively over network play. The game follows the progress of the host player, rewarding the other active players for completion of quests for their characters. When more players are present, the game alters the statistics of the generated enemies, balancing the game due to the larger number of players.