The gameplay in Resident Evil 3 is essentially the same as previous installments with only a few minor adjustments to core mechanics. Unlike the first two games, the player is unable to choose one of two playable protagonists, instead playing solely as Jill. Akin to previous titles in the series, the player is able to control a supporting protagonist -- Carlos Oliveira.
Resident Evil 3 also introduces the 180-degree spin action that allows players to swiftly turn and retreat faster through a simple button combination. This was later implemented in future installments. It also introduced the dodge move where the player can dodge an enemy's encounter. It's a very useful feature because enemies in this game are faster and can now move on stairs.
It was also the first game in which the player can go up stairs without having to push a button on the controller. All the later games had this feature with the exception of CODE: Veronica.
Resident Evil 3 also introduces 'Live Selection'. At certain points in the game, the player will have two choices, usually bringing the game to another twist such as alternative enemy placements or new cutscenes. These decisions do not affect the games ending. This is also the only game in the Resident Evil series to use the 'Live Selection style' of play.
Another entirely new feature is making ammunition with Gun Powder that the player finds lying around. The gunpowders are labeled type A, B, and C (C is crafted, not found). A-type gunpowder is handgun bullets, B-type gunpowder is shotgun shells, and C-type gunpowder, which is created by mixing A and B together, make standard ammunition for the Grenade Launcher. Also combining gunpowder to normal grenade rounds will create special grenade rounds: A type powder-Flame rounds, B type powder-Acid rounds, C type powder-Freeze rounds. The player can experiment with mixing different types of gunpowder together to make different types of ammunition, e.g. Magnum Bullets can be created by mixing type C, C, and C together. When the player is done mixing the powders together, the player can use the Reloading Tool to create the ammunition. (The more times the player creates bullets with the Reloading Tool, they will eventually be asked to make more powerful ammunition).
Another new feature is the ability to attack certain objects in the environment, such as oil drums, causing them to explode and dealing severe damage to or killing any enemies in their vicinity. This can be helpful in situations where the player is cornered by a large group of enemies.
Resident Evil 3 also added randomization to the gameplay. Some items such as ammo, medicine, and even some weapons did not have a fixed location, but would instead appear in different areas. The enemy placement could also change from one playthrough to the next. The player choice could also affect the storyline even to the ending.
At certain points in the game, the screen will turn white and the player will enter Live Selection mode. The Live Selection Mode will prompt the player to choose between one of two possible actions. Choose wisely and choose fast because there is only a limited amount of time to make the decision. Most live selection modes occur when the Nemesis finds the player or gets the player into a situation. Choosing a certain situation will incapacitate the Nemesis, although most of the time it will rise again shortly where it will continue to violently pursue the player. During this time, the player can pick up gun parts or items from him that he might be carrying. For example, when Jill is in the kitchen hiding from the Nemesis the player can choose to ignite the gas, blowing up most of the building. Nemesis will be incapacitated when the player comes out of their hiding spot. There is no decision that the player can make that will cause Jill to die, however, if no decision is selected by the time ends, Jill will either incur damage or be forced to fight an enemy [most of the time involving Nemesis]. Sometimes not choosing is useful because it could put you in a more suitable fighting arena than the one you may encounter if you choose one of the two options.
There are three individual factors in Resident Evil 3: Nemesis that determine a ranking: Playtime; the number of saves, and the total amount of HP restored with health items. Each of these factors results in a number of points. The final score is the sum of the points of all three factors.
2:29:59 or less
1500 or less
10:00:00 or more
3350 or more
As can be seen, someone taking more than 10 hours to finish the game, but who don't save and avoids injury can beat the game with 200 points, giving them a B rank.