Pennsylvania’s school funding has been ruled unconstitutional — both for depriving children in poorer communities of the education to which they’re entitled and for shortchanging them compared to peers in wealthier districts. A fix could take years and cost the state billions of dollars, depending on how lawmakers respond to the Commonwealth Court decision.

But if you look at other states’ funding formulas and the systems supporting them, it’s clear the solutions — shaped by a patchwork of court rulings and the political dynamics at play — run the gamut. Even efforts once lauded as successful may still fail, as states don’t always follow through on what their formulas, or their courts, say is required.

In some states, that’s led to more striking interventions: The North Carolina Supreme Court, for instance, last year ordered the transfer of $1.75 billion from the state’s treasury to implement a school funding plan. Washington’s high court in 2015 fined the state’s legislature $100,000 a day for failing to make progress on a plan.

States have been repeatedly dragged back to court: In Kansas, plaintiffs’ lawyers made 13 trips to the state Supreme Court. Battles over school funding have led to improvements, advocates say. But experts say no state has a perfect system, and some remain deeply flawed.

While Pennsylvania — where state officials could still appeal the recent ruling — faces what could be a long road to reform, here’s a look at other states’ approaches and what’s working (or not) and why.