Momentum is a basic ability associated with the Constitution skill. When activated, all auto-attack damage is increased by approximately 20% and basic abilities of the relevant combat style will be triggered automatically until the ability is deactivated. Momentum can be deactivated by either re-using it outside of combat, or by using any other ability. The abilities bar may be minimised to discourage ending the effect on accident, unless the player has no abilities hot-keyed, or if the player wants to deliberately have a way to end the effect through using an ability. Additionally, auto-attacks and abilities under the effect of Momentum will not generate any adrenaline, nor will the first ability used to trigger cancelling of the effect. However, activating Momentum with adrenaline remaining will drain it completely. Like Incite, Momentum is persistent between log-ins, and it will last indefinitely once it is activated.
The basic abilities triggered while under the effects of Momentum are limited. For melee, only Slice, Dismember, Punish and Sever apparently have a chance of being randomly performed. For ranged, Piercing Shot, Binding Shot and Fragmentation Shot are randomly performed. For mage, it appears that only Impact, Wrack, and Combust are randomly used. The damage of random abilities are not boosted. In addition, any basic abilities in melee or ranged that you meet the requirements for can also be randomly performed. For example, dual wielding two swords enables you to use the ability Havoc. It is worth noting that Momentum will not trigger any basic defence abilities such as Resonance or Anticipate even if a shield is equipped, regardless of combat style.
Momentum was added to the game during the beta stage of the Evolution of Combat in a response to players' need for "a less input-intensive way to grind through long Slayer tasks". It was aimed to give the 'old-style' combat a place after the EoC, yet it must be noted that momentum attacks are notably weaker than ability attacks and are strongly not recommended for PVP.