Louis Lefebvre
Game Designer
System designer and Content designer. I strive to make high quality games with a lasting impact on players.
The importance of root motion
In an action RPG combat based game, one of the key features of an attack is the distance covered by the character during an attack.
This is determined by the root motion imputed by animators.
As a GD, our role is to design the functionality of the attack in conjunction with the animators. So how should we go about these decisions ?
Let's make a case study of two very similar attacks from elden ring to see what attacks with a similar role and similar type of weapon (a polearm) feel good or bad.
This first exemple is the first light attack of the Guardian tree swordspear’s light attack combo. Which is using a moveset considered “good” by the community
As we can see, the attack itself covers a lot of surface and the weapon has a lot of range which makes it very useful against all types of enemies or encounters. It helps against crowds of enemies but also against single big enemies. Moreover the attack has an upward motion which helps with all the giant enemies of the game.
To compensate for this gigantic surface covered by the attack, the root motion of the animation is quite small and the player doesn’t move much forward. It is also placed towards the middle/ end of the attack itself which allows for a rotation mid attack, helping again to not whiff the attacks.
The second attack is also a first attack of a light attack combo. The yari uses a variant of the spear moveset. As we can see it covers a lot of vertical surface but way less horizontal. However, it has a lot more root motion than the teeguarden's swordspear attack, thus augmenting the surface covered by the attack which compensates for both the lack of horizontal coverage and helps connect with the attack as vertical attacks make gauging the distance more complicated.
Furthermore, the root motion is placed at the beginning of the attack, that creates a smooth transition from any previous speed and gives the impression that the attack comes out “faster”
In both cases the attack is a light attack. What purposes does it have?
The light attack should be fairly quick, deal a reasonable amount of damage. Since this one is the first one of a longer combo, it should flow into the second attack but also have an excellent gamefeel since it is likely the attack that will be the most used of the light attacks.
Finally a very important point: the first attack of the light attack combo can be used from a lot of different speed, but most likely at either very low speed (character not moving) or the highest speed authorized without sprinting.
Per our analysis of those 2 different cases, we can see that although the one from the the sword spear has a very good coverage of surface with the attack, the little root motion, place where it is does not fit the role of a first light attack well. In fact, the fact that the root motion is placed towards the active part of the attack, where the player moves the weapon is a disservice to the gamefeel when using the attack while moving forward. The character has a hard stop which feels frustrating and stops the flow of movement. This is less of an issue in static combat, as the difference between the character’s speed during movement and the average speed felt during the light attack is less important.
The second attack fits way better into its role as a combo starter as the root motion is more towards the start of the attack. Moreover the root motion slows down towards the end of the active part of the attack, which creates a “cushioning” effect helping ease the perceived speed into the speed of the next attack, even if the character was at max movement speed.
To conclude, we can see that in this case, the root motion placement and its value changes a lot the perception of the attack from the player. The earlier the root motion is, the quicker the attack will feel, and make the transition between movement and attack feel good. If the root motion has a high value, or the attack combos into another one, the attack needs to have a sort of cushioning effect to ease the attack’s speed into the average perceived movement speed in the combo . Of course any other attack that transitions from movement to combo needs to take into account the previous speed, a running attack will have more root motion for example.