Functionally SWTOR operates exactly the same as World of Warcraft and similar MMOs. There are 50 levels to gain, multiple classes and roles to play, and a system of combat that requires clicking on or using keybinds to activate skills.
This similarity to the leaders in the field will help with the transition from one of those older games to this one, but it also means that those expecting a truly different experience will probably be disappointed. This is BioWare's first MMO and it decided to go with the tried and trusted formula, which, considering World of Warcraft's millions of players, is probably not a bad idea.
Exploration is primarily a ground affair, despite the use of starships to travel from planet to planet. BioWare has spiced up exploration by adding location-based lore entries into its codex and stat-improving Datacrons, which are hidden throughout the landscape and sometimes involve an element of puzzle to unlock. Players should not expect a sandbox experience, however, especially those coming from Star Wars Galaxies, as SWTOR is very much a themepark style MMO the does not feature, for example, endless deserts.
The class-based story can at times make the game feel like a single-player experience, but there is plenty for groups to do, including heroic quests in areas that will result in an untimely end for solo explorers, four-person flashpoint instances, and eight-player and 16-player operations to fill the needs of casual raiders and raiding guilds.
Player-versus-player (PVP) combat is also catered for in multiple ways, most notably of which is a number of warzones, where people can do straight-forward player killing or take part in more interesting arenas where players have to carry a ball around an obstacle course. Open world PVP is also available on special PVP servers or if a user flags their character on a player-versus-environment server, but BioWare has failed to solve the problem of high level players killing newer players who are trying to quest on PVP servers.
This is all pretty standard fare for an MMO, but BioWare has added its own little twists, like group dungeons having the potential to be different each time by choosing different dialogue options. Group players are also rewarded social points for participating in dialogue dice rolls, points which ultimately can reward in some fun cosmetic items.