Houston Oiler quarterback Dan Pastorini and Baltimore Colt defensive end John Dutton became free agents yesterday. The deadline passed for National Football League clubs to decide whether to keep players entering their option year or to make qualifying offers to those who had played out their options.

Including Dutton and Pastorini, 122 NFL players became free agents yesterday.

Pastorini's agent said the quarter-back was close to signing with the Oilers but would listen to offers from other clubs.

The Baltimore New American reported that the Miami Dolphins might be willing to pay as much as $200,000 to sign Dutton.

There are three categories of free agents.

Most are those who played out the option years of their contracts last season but have been made "qualifying offers" by their 1977 clubs.

That means those clubs will have an opportunity to match the ofer of any new club. If the old club decided not to match such an offer, the new club would have to compensate the old club with draft choices.

The compensation is scaled, according to how much salary the new club plays the player.

The second category includes those who played out the option years on their contracts last season but were not made qualifying offers. A new club signing any of those players would not have to pay compensation to the new club, except for those players with considerable longevity.

The third category comprises veterans who were coming up to the option year of their contracts in the 1978 season, but whose old clubs did not exercise the option to keep the player for the option year.

Players in that category are free agents. The old club is not entitled ot compensation if a new club signs a player in that category.

Transactions announced yesterday:

BALTIMORE - The Colts announced that safety Lyle Blackwood, as well as Dutton, was made a qualifying offer.

Houston - Besides Pastorini, the Oilers made qualifying offers tolinebacker Gregg Bingham, offensive linemen Gregg Sampson and Elbert Drungo, defensive backs Mike Reinfeldt and C.L. Whittington and quarteback John Hadl. They did not make offers to injured running sack Fred Willis or reserve blackkicker Tom Dempsey.

SEATTLE - Of 10 veterans made free agents, the Seahawks said three were not made qualifying offers, but would not identify them. The free agents were safety Aurty Beamon, offensive tackle Nick Bebout, defensive linemen Ron East, Bob Lurtsema and Alden Roche, punter Herman Weaver, running back Ed Marinaro. Thebacker Amos Martin, defensive back Don Dufex and offensive lineman Horace Jones.