of what would later be called "crossover thrash", along with Adrenalin O.D., with both bands having a heavy influence on modern thrash metal. To date, D.R.I. has released seven full-length studio albums. Other than three new songs on the 2016 EP But Wait... There's More!, they have not released a full-length studio album since Full Speed Ahead in 1995. Despite this, the band has continued to tour almost every year, and gone on hiatus intermittently, notably between 2004 and 2009, when Cassidy was diagnosed with colon cancer. Since at least 1998, D.R.I. has been working on their eighth full-length studio album, which remains unreleased.

D.R.I.'s music has combined elements of punk rock, thrash metal, speed metal and heavy metal, while their early material has been described as hardcore punk. They are often cited as one of the key bands that helped create the crossover thrash genre, along with S.O.D., Suicidal Tendencies and Corrosion of Conformity. Allmusic.com has claimed that, "Starting off as a speedy, straight-ahead punk band, they gradually mixed more elements of heavy metal into their sound; as they did so, their songs got longer and featured more sections and more variety in tempo. D.R.I. managed the then-rare feat of crossing over to metal audiences while retaining their skate-punk and hardcore fan bases -- they had something for all those audiences to love (or hate)." Many bands and artists have cited D.R.I. as an influence or inspiration, including Anthrax, Cryptic Slaughter, Dark Angel, Death Angel, Kreator, Municipal Waste, Nuclear Assault, Slayer and Vio-Lence.

When Felix joined D.R.I. in 1984, he brought a new audience to the shows. The next three years the band toured and started developing a new genre, (along with other pioneers) crossover. Their third album, Crossover, released in 1987, was suitingly named, as the songs on this album had a strong metal sound to them. As the band began to "crossover" to thrash, their songs became longer, slower, and more complex. The press has called D.R.I. the major band of the "crossover" movement, a style that combined hardcore punk and thrash metal. This music invited a mixed audience of punks, skinheads, and metal fans to their shows.