Act of Senedd Cymru

In Wales, an Act of Senedd Cymru (), or informally Act of the Senedd, is primary legislation that can be made by the Senedd (Welsh Parliament; ) under part 4 of the Government of Wales Act 2006 (as amended by the Wales Act 2017). Prior to 6 May 2020 any legislation was formally known as an Act of the National Assembly for Wales () or informally, an Act of the Assembly.
The power to make primary legislation was conferred on the assembly following the 2011 elections as a commencement order had been passed in the Assembly by simple majority prior to dissolution. The activation of part 4 legislative powers was as a result of a "yes" vote in the 2011 referendum held in Wales. When the power to make Acts of the Assembly commenced, the Assembly lost the ability to make Measures under part 3 of the 2006 Act. Existing Measures will remain as law unless repealed.
The current name was adopted when the Senedd and Elections (Wales) Act took effect on 6 May 2020, which renamed the "Acts of the National Assembly for Wales" stated in section 107(1) of the Government of Wales Act 2006 as officially "Acts of Senedd Cymru" (plural ) and informally referred to as “Acts of the Senedd”.
How Acts are made.
Consideration by the Senedd.
Bills may be introduced by Welsh Government, a committee of the Senedd, the Senedd Commission or by individual Members of the Senedd. Ballots are held to select which individual Senedd members may present bills. 
Once a bill is introduced, there are four stages that need to be completed prior to the bill being submitted for royal assent. The first stage involves consideration of the general principles of the bill by a committee of the Senedd and then agreement of these principles by the Senedd in plenary session. In the second stage, the bill is considered in detail by a bill committee. The third stage involves detailed consideration of the bill and any amendments by the Senedd in plenary, this can be followed by a Report Stage where further amendments can be proposed. Finally, in the fourth stage, the Senedd votes to pass the bill in its final form.
Period of intimation and Royal Assent.
When a bill completes its passage through the Senedd, it enters a four-week period of intimation, during which the Attorney General for England and Wales or the Counsel General for Wales may refer the bill to the Supreme Court of the United Kingdom if they consider that any provisions of the bill are outside the legislative competency of the Senedd. The Secretary of State for Wales may also make an order prohibiting the Clerk to the Senedd from submitting the Bill for royal assent during this time. After the period of intimation expires, the Clerk may submit the bill for royal assent. The bill becomes an Act of the Senedd when Letters Patent under the Welsh Seal are made by the Queen to signify assent.
Form of letters patent.
Royal assent to Acts of the Assembly was given by means of Letters Patent using the following wording:
The Letters Patent may also be made in Welsh:
Enacting formula.
Acts of the Assembly begin with the following words of enactment: 
Subjects in which Acts can be made.
Under the Wales Act 2017, the Senedd has legislative competence to pass Acts on any matter relating only to Wales that is not a reserved matter, or which affects powers exercisable other than in relation to Wales. The list of reserved matters is extensive; it includes:
Additionally, unlike Acts of the UK Parliament, an Act of the Senedd is "not law" if it is inconsistent with the European Convention on Human Rights.
Subjects of Measures.
Part 4 of the Government of Wales Act 2006 gives the Senedd legislative competence in the following 20 "Subjects" outlined on schedule 7 of that act in relation to Measures. (The Senedd does not have competence with respect to all aspects of these subjects.) Since the Assembly gained the competence to pass Acts, these have not been used, but they still apply in relation to previously passed Measures.