How laws are made changes from country to country. However, in every case, a law must still be written and passed by the legislative branch of government, and signed into law by the executive branch of government. What changes is how these two branches of government are distributed and how many people are involved at each step. In a pure dictatorship, both legislative and executive branches of government may be vested in a single person and his circle of advisers.
In the United States, the making of laws is the chief function of the House of Representatives. Any member of the House may introduce legislation at any time by placing it in the 'hopper' at the side of the Clerk's desk, which will then be assigned a legislative number and referred to the appropriate committee or subcommittee. Other representatives may also co-sponsor the legislation. Legislation is proposed in one of four forms: the bill, the joint resolution, the concurrent resolution, and the simple resolution. Which form is used depends on the substance of the legislation.
In committee, the proposed legislation is scrutinized closely. Members of the public can have their input on the proposed legislation at this time, during scheduled public hearings. After the hearings, the committee holds a 'mark-up' session during which amendments may be added to the legislation. Each amendment is voted on separately. Finally the committee votes on the entire piece of legislation to determine whether the legislation will be reported for House consideration or tabled. An urgent piece of legislation may be brought to Congress directly.
A committee chair can hold up a bill indefinitely by never placing it on the committee's agenda for consideration. In the same way, the Speaker of the House can choose to delay bringing a proposed piece of legislation to the floor. However, it may still be introduced to the floor by means of a discharge petition. In this case, the proposed legislation is brought directly to the floor after the committee is 'discharged' from further consideration of a bill. A discharge petition can also overrule the Speaker by making a special rule providing that a reported measure that was never called for consideration be considered. To pass, a discharge petition requires the support of an absolute majority of House members.
The House now debates on the proposed legislation, and may also propose its own amendments. Again, each amendment is voted on separately. After all debate and amendments have been resolved, the House votes on whether the proposed legislation will pass on to the Senate, whether it will be recommitted to committee, or whether it will be tabled.
The Senate goes through the same procedure. If the Senate approves an amendment to the legislation, it must be returned to the House to be voted upon anew. If it is an urgent piece of legislation, it can be returned directly to the floor of the House. In case of back-and-forth changes to urgent legislation, a conference committee may be appointed, consisting of both House and Senate members, to resolve the differences and present a final version of the legislation to both houses. All other proposed legislation takes a new place in the queue.
After the proposed legislation has passed both houses in the same form, it is considered to be 'enrolled.' At this point it is presented to the president, who usually signs it into law. The president also has the option to let the proposed legislation become law without his signature, which happens after ten days (not including Sundays), or to veto it and return it to Congress. In this case, Congress can overrule the veto by a two-thirds majority in both House and Senate.
If Congress is scheduled to adjourn within the ten day period, the president also has a third option: he can exercise a pocket veto. A bill which is not signed into law in the ten days before Congress adjourns does not become law. This is even stronger than a veto, because Congress cannot overrule it. For this reason, the Supreme Court has ruled that Congress can appoint agents to receive the veto, so long as Congress is able to act on the veto with "reasonable promptness." Most presidents choose not to pursue a disputed pocket veto, lest an adverse Supreme Court ruling create a precedent.