SSX 3 is a snowboard racing game played from a third-person view. Players control one of various snowboarders and compete in events set across individual courses in peaks on a mountain. Unlike previous games in the series, which contain unconnected courses, a freeride mode also allows players to freely roam the open world consisting of all the courses in the game; it is possible for the player to ride from the top of the mountain to the bottom without stopping or reloading each course. New areas are progressively unlocked throughout the game.

Players can gain points by performing tricks, such as grabs, grinds, flips, and spins. A feature returning from previous games in the SSX series is the adrenaline meter, which gains adrenaline when the player executes tricks. It can be used to provide a speed boost or, once it becomes full, perform advanced tricks called übers, which grant more points than regular tricks. Performing übers increases the level of the adrenaline meter, which leads to progressively more advanced super über tricks and faster adrenaline boosts. Performing multiple tricks of different kinds creates a combo, doubling the points acquired from tricks, while repeating the same trick causes the number of points it earns to drop. Landing tricks poorly or hitting an object in mid air will cause the snowboarder to wipe out, falling over. The player has the ability to recover their snowboarder more quickly by tapping a button, or alternatively reset the snowboarder back to the course if they get stuck in an area. Both wiping out and resetting result in a loss of adrenaline and the ability to perform übers until the adrenaline meter is filled again.

Players complete peak goals—set objectives—to progress through the single-player mode and unlock all three peaks of the mountain. Peak goals are achieved by completing events, earning money or completing big challenges and finding collectables, both during freeride mode, which can be accessed outside of events. The player only has to complete one of these goals to progress to the next peak. Completing each peak goal unlocks a trophy for the player.

Each course in the game has a designated event that players can compete in. Events fall under two categories: race and freestyle. Coming first in an event provides the player a gold medal, coming second provides the player a silver medal, and coming third provides the player a bronze medal. It is also possible to obtain a platinum medal by beating certain times or getting a high enough score. The race event objective is to get to the end of the course as quickly as possible. Players race against other snowboarder NPCs on the same course.

Races contain multiple routes and shortcuts, which can give the player an advantage over opponents. Players can also use melee combat to knock other snowboarders over, slowing them down and providing the player with adrenaline. Race events have three heats, and the player must come third place or above in each heat to progress. Once all race events are completed on a peak, the player's snowboarder is challenged to a backcountry race by their rival snowboarder. Winning unlocks a peak race, where the player aims to beat their rival's best time from the peak to the bottom of the mountain; both races have only one heat. Completing the races unlocks the next peak.

The freestyle events include slopestyle, big air, and super pipe. Their objectives are to get as many points as possible. Slopestyle courses are similar to race courses, as players must ride through a downhill track with multiple paths. While the goal of slopestyle courses is for the player to gain points by performing tricks, big air courses are short, with one or two ramps that are designed to allow the player to perform large jumps and multiple tricks in a small amount of time, and super pipe courses contain half-pipes that the player can repeatedly perform tricks on. Freestyle events are structured similarly to race events; each have three heats, and the player is invited to backcountry jams and peak jams, where points are scored through performing tricks. Completing the freestyle events unlocks the next peak.

Outside of events, players can take part in big challenges. The objectives of the challenges include jumping through hoops and collecting items, among others. Collectable crystals items can also be found on every course, and can be collected in any event and in freeride. Obtaining enough crystals and completing enough big challenges on a peak unlocks the next peak. In addition to peak goals, SSX 3 contains smaller challenges called career highlights. Similar to big challenges, objectives can vary, and include holding a handplant for five seconds or doing a certain number of übers in one event. In freeride, players can travel to any courses they have unlocked and can also go to stations; these areas contain lodges, which allow the player to save their game, edit music playlists, buy attributes to improve their snowboarder, purchase new übers, and buy or equip gear and boards to change the aesthetics of the snowboarder. Money can also be used to buy extras, such as videos, cheat characters, and game art. Money can be earned in game by performing tricks, completing big challenges and events, or collecting crystals. Earning enough money on a peak will unlock the next peak. In station areas, game narrator DJ Atomika talks to the player via EA Radio Big, a fictional radio station. He gives the player information about events and weather, as well as other miscellaneous information. While the player is on a course, the soundtrack of the game is played through EA Radio Big. Depending on how well the player is performing, the music becomes quieter and louder. The player can change what music is allowed to play at lodges.

The PlayStation 2 version of SSX 3 had an online multiplayer mode that allowed two players to race against each other over the internet. The service required an EA account to use. Players could join lobbies, where they could challenge players to races, view player statistics such as the global rank of a player, and chat with players using supported USB headsets and keyboards. Players could send messages and add up to forty friends, called buddies, using EA Messenger, an in-game instant messaging service. The online service has since been discontinued.