The Governor may expand his Call to include additional topics at any time (Texas Constitution Article 3, Section 40).
Other than the Governor opening the Call, any bills that were vetoed during the 88th Session or other legislation that could be filed outside the bounds of the Governor’s Call are subject to the Texas Constitution and the House and Senate rules.
Article 3, Section 40 of the Texas Constitution states: “When the Legislature shall be convened in special session, there shall be no legislation upon subjects other than those designated in the proclamation of the Governor calling such session, or presented to them by the Governor.”
The House and Senate rules note traditionally that only legislation put forth in the Governor’s call will be considered, though interpretations of rules may differ. The rules appear to not limit what is filed but, rather, limit what legislation progresses.
The Legislative Reference Library has compiled an FAQ for rules of interest to the 88th Special Session.
House
The explanatory notes under Texas House Rule 8, Section 21, state that traditionally the legislature has broad discretion within the boundaries of the subjects submitted by the Governor during a called session. However, the speaker may be required to determine if the legislation is within the parameters of the governor’s call. The notes also lay out two distinct plans of procedure. The first scenario is the current practice where the speaker gives all introduced bills a first reading and then refers them to appropriate committees without regard as to whether they fit within the stated purposes of the called session. This procedure does not diminish the right of a member to later challenge a measure on the ground that it does not relate to a subject submitted by the governor. Under the second scenario, “the speaker reviews all bills filed with the chief clerk, or coming from the senate, to determine if their subject matter has been submitted by the governor. He will then admit to first reading only those that are so covered.”
Senate
In regards to Senate rules, the Senate may not grant by vote or by unanimous consent permission to a member to introduce a bill not within Governor’s call (Senate Rule 7.04)
Furthermore, a point of order, made and sustained at a special session, that a bill (which has been read second time) is not within the Governor’s call, prevents any further consideration of it at that session (Senate Rule 7.04).
Length of Time for a Special Session:
Although special sessions are limited to a maximum of thirty days, the Texas Constitution does not impose a minimum (Texas Constitution Article 3, Section 40). The 1st called special session of the 38th Legislature met for only one hour and no legislation was enacted. (Legislative Reference Library).
Veto Time Period:
The Texas Constitution, which grants the Governor the power to veto bills and delimits the period of time he/she has to exercise that power, draws no distinction between regular and special sessions (Texas Constitution Article 4, Section 14).