Overall Engine

At its core Rock Band 3 still plays much like its predecessors, however there have been a few changes to the game's main engine.

Unison Bonuses
Unison bonuses in band play still work the same as they did in the past, with an extra quarter bar of overdrive being awarded to everyone if all players hit the notes under the unison section. Players will now also receive this extra bonus in solo play, with all overdrive phrases that are unison bonuses in band play having a gold outline to them to indicate that they give a half-bar of overdrive.

Star Cutoffs
Due to more points being possible with more overdrive present in the chart, star cutoffs have been adjusted in order to compensate for this. Even with the generally raised cutoffs, most songs seem to be slightly easier to gold star than before. This seems to be particularly noticeable on bass. Cutoffs now seem to also factor in how many points a player would receive for a 100% solo bonus, causing any songs with solo sections to be more difficult to gold star than they may have been in previous games. For example, "Free Bird" is nearly or completely impossible to gold star on guitar without receiving the 100% solo bonus on the long solo at the end of the song.

Rock Meter
Overall the rock meter feels a bit stricter in Rock Band 3, making it take less missed notes to fail out of a song. Thankfully you can either continue playing the song from where you failed and not receive a score, or toggle on no fail mode and restart the song.

The "Strum Limit"
After being a popular topic for debate for ages, the alleged strum limit seems to have finally been fixed in Rock Band 3. For those unaware, the strum limit was the term coined to describe the effect of the timing window seeming to shrink on notes that are extremely close together and making them exceedingly more difficult to hit. At very high speeds, this made certain fast strumming sections nearly impossible to hit which resulted in all the songs remaining to be full comboed (FCed) only being that way due to their fast strumming portions. Less than 2 weeks after the release of Rock Band 3, all of these remaining songs have been full comboed after months, or in some cases years of not being done.