A soft salary cap allows teams to exceed a spending limit, so a second mechanism is needed to make exceeding it costly. The luxury tax is that mechanism.
The threshold sits above the cap
Two separate lines exist. The salary cap governs which signing tools a team may use, and the tax threshold, set higher, governs what spending costs.
A team may operate between the two without penalty, which is where a large share of the league usually sits.
Both lines move with league revenue, so a team's status can change without its payroll changing at all.
The rate escalates deliberately
Tax is charged per dollar above the threshold, at a rate that increases in bands the further a team goes.
Escalation means the marginal cost of one additional contract rises sharply, which is the point. A flat rate would simply be a price wealthy owners would pay.
Repeat-offender provisions raise the rates again for teams that have paid in several recent seasons, targeting sustained rather than occasional spending.
The proceeds go to teams, not the league
A substantial portion of collected tax is distributed among teams that finished below the threshold, with the remainder used for league purposes.
This is what makes the tax a redistribution. Owners who spend less receive money from owners who spend more, which changes the politics of the rule.
It also gives every team below the line a direct financial interest in staying there, which reinforces restraint independently of competitive concerns.
Second thresholds add non-financial penalties
Recent agreements add higher lines above which teams lose access to roster-building tools entirely, regardless of willingness to pay.
Restrictions on signing free agents, aggregating salaries in trades and using exceptions are more binding than money for an owner with deep resources.
Draft-pick penalties operate the same way, converting a spending decision into a cost the owner cannot simply absorb.
Behaviour changes around the line
Teams manage payroll to finish below the threshold on the date it is measured, which produces trades whose purpose is accounting rather than basketball.
Contracts are structured with that date in mind, and the timing of a deal can matter as much as its terms.
The tax therefore shapes the transaction calendar as much as the payroll. Any threshold measured on a single day creates activity clustered immediately before it.

