Direito Constitucional
Core concepts
Distinguish diffuse control (any court, concrete case) from abstract control (STF; ADI, ADC, ADPF, ADO), plus repercusso geral as a filter for extraordinary appeals and súmula vinculante (art. 103-A) binding the Administration and the Judiciary. Know the legitimados of art. 103, including entities of class with pertinencia tematica. Clauses petreas (art. 60, §4) cannot be abolished but may be modified in a way that preserves their core; effects may be modulated (art. 27 of Lei 9.868).
Organisation: Union competences of art. 22, common of art. 23, concurrent of art. 24. Judicial guarantees are vitaliciedade, inamovibilidade and irredutibilidade; the juiz das garantias (Lei 13.964) is a good example of modulated effectiveness. Fundamental rights have a double dimension and are limited by proportionality.
Traps
A classic trap is the abstrativizacao of diffuse control (ADIs 3.470 and 4.097): a concrete decision may gain general effects after the repercusso geral ruling. Another is to treat ADPF as a substitute for ADI in every case, although the Court has admitted parametric ADPF. Also, binding effect does not prevent the legislator from enacting new laws on the subject.
Rule of thumb
In constitutional control questions, ask: who may sue, what is the object, and what are the temporal effects? Worked example: a state law is the object of an ADI; a municipal law violating the Federal Constitution normally requires diffuse control or a specific ADPF hypothesis.