Roster space refers to the number of available roster "slots" in NBA Live. Beginning with NBA Live 97, the game has reflected the NBA's limit of fifteen players per team with three inactive roster slots. Teams with roster space can sign free agents without releasing any players first - depending on how many slots are available - and make trades involving an uneven number of players such as one for two, two for three, etc. In Dynasty Mode, CPU teams that do not have a full fifteen player roster (and thus have roster space) are valuable when trying to clear cap space or make difficult deals that require additional players to balance salaries.
History of roster slots in NBA Live's roster management
In NBA Live 95, there were no inactive roster slots and teams only had twelve players. As such, there were no empty roster slots for use in trades and all 27 teams had the same amount of players. NBA Live 96 expanded the rosters to fourteen players with two inactive roster slots as well as a Free Agent pool where teams could release players. The Free Agent pool itself only had fourteen slots of its own however, making it far more restrictive than in later games. The introduction of empty roster slots allowed users to trade playrs to teams without receiving a player in return, a handy feature when making roster patches or manually updating teams in Season Mode.
NBA Live 97 expanded the roster to fifteen as well as eliminating the use of roster slots in the Free Agent pool, while retaining the ability to trade for empty roster slots. This would remain unchanged through NBA Live 2001, which also added the ability to place less than twelve players on the active roster. Previously, the only way to access the inactive roster was to have at least thirteen players with only twelve appearing on the active roster. This feature has not been implemented since NBA Live 2003.
Beginning with NBA Live 2002, users have not been able to trade players for empty roster slots (essentially making deals for cash) either in Dynasty Mode or when editing the default rosters, however with the introduction of trading draft picks in NBA Live 2004 it is possible to trade a player for a pick, so long as the team trading the pick has an empty roster slot.