Virginia voters will decide Tuesday whether to expand the number of people in line to become governor in the event of a terrorist attack or other disaster, and they will vote on a change in the rules governing special elections after a redistricting.

Both choices will be on the ballot in the form of amendments to the state constitution. Voters statewide will be asked to vote yes or no on each of them.

The succession amendment, which will be listed second on the ballot, was drafted by a group called the Secure Virginia Panel created by Gov. Mark R. Warner (D) in the wake of the Sept. 11, 2001, terrorist attacks.

Virginia's constitution lists three people in line to take over if the governor is incapacitated: the lieutenant governor, the attorney general and the speaker of the House of Delegates. If none of them could serve in the governor's place, the constitution requires that the House meet to elect a new governor.

The proposed amendment expands the list. It allows the House to designate a person to serve if the speaker cannot. If that person is unavailable, the president pro tempore of the Senate would take over -- and after that, the majority leader of the Senate. Under the new constitutional provisions, the successor would remain acting governor until the House met to elect a permanent replacement.

The other constitutional amendment, which will be listed first on the ballot, was drafted in response to a bizarre election result three years ago.

Redistricting in 2000 had meant the loss of a state Senate seat in the sparsely populated southwest part of Virginia and the creation of a new Senate seat in the burgeoning areas of western Fairfax County. Because of the timing of elections, Madison E. Marye, a Democratic senator who had represented five counties of southwest Virginia, continued to serve even though his district had shifted hundreds of miles north to Fairfax.

That was challenged in court by Fairfax residents, and the lawsuit was dropped when Marye retired. Then Marye himself filed suit, on behalf of his southwest district voters, to maintain their representation, but he was unsuccessful.

A special election went forward in Fairfax County, but that effectively left the people in southwest Virginia without a senator for whom they had voted.

The new constitutional amendment would require that any vacancy after a census and before the next general election be filled from the same district that elected the representative in the first place. If that had been law at the time, Marye's departure would have prompted a special election to replace him in southwest Virginia.

"It's an innocuous little thing, but it does need to be fixed," said Sen. James K. "Jay" O'Brien Jr. (R-Fairfax). O'Brien was elected to the Senate from Marye's district after it moved to Fairfax. "Although I was the beneficiary, it was entirely inappropriate to have special elections in new districts in midterm after redistricting."

Both constitutional amendments must be approved by a majority of voters casting ballots Tuesday for them to take effect.

Madison E. Marye's suit on behalf of his former district helped spur a constitutional amendment this year.