Pavel Pogrebnyak was dismissed in the first half for the hosts before Leonardo Ulloa received a straight red card for his challenge on Alex Pearce
Chances proved hard to come by at both ends in what was a bad-tempered affair that saw eight yellow cards and two players sent off.
Reading striker Pavel Pogrebnyak, making his first start of the season, was first to see red after earning a second booking for simulation just after the half-hour mark.
And just eight minutes later, both sides were down to 10 as Leonardo Ulloa was shown a straight red card for a dangerous tackle on Alex Pearce.
Both teams' best chances came after the break, with Danny Williams threatening for Brighton from a header, while Ashley Barnes also brought a good save from Alex McCarthy from his close-range effort.
It was the first match of the season in which Oscar Garcia's Brighton have failed to score, and last season's play-off semi-finalists drop a place to 14th after the weekend's action.
Reading, who have now conceded just one goal in their last three games, sit ninth.