I just need to know if the randomness of the dice is part of the BG3 combat or not.
Yes it is.
BG3 is built on the D&D ruleset which uses dice for most actions, be it picking dialogue options, trying to detect traps and combat.
There is a lot of randomness that is thus included, especially given the ruling of Natural 20 and Natural 1 rolls on the standard D20 (Whereby Nat 20 is auto success and critical hit and Nat 1 is auto fail) creating scenarios where no matter what you do there's a 5% chance for a undesirable outcome.
However, unlike WotR, BG3 is working off of D&D's 5th Edition ruleset rather than the 3.5 Edition of Pathfinder. This has a more streamlined (I.e. Simpler) approach to the overall ruleset which is easier to get used to. In addition, Larian has done a considerable amount of homebrew (Deviating from the actual ruleset) which adds some more Divinity-esk flavour to the game.
As such, it's possible you might enjoy the game despite its D&D basis and the inherent RNG from dice rolls.
