Polyelectrolyte complexes (PECs) form spontaneously upon mixing aqueous solutions of oppositely charged polymers, forming a polymer rich complex phase and polymer poor supernatant phase. PECs are promising material platforms for various industrial applications due to their biocompatibility, low surface tension and stimuli-responsiveness. Molecular design also allows us to design core-shell micelle systems with polyelectrolyte complex cores and hydrophilic coronas, named polyelectrolyte complex micelles (PCMs). However, there are currently few predictive design principles that allow for rational PEC design, limiting the adoption of PEC technologies. Here, we aim to investigate molecular architecture to develop chemically agnostic design principles that work consistently across various chemistries. In Chapter 1 of this dissertation, we discuss the relevant background information and highlight influential work in foundational PEC concepts, the use of non-linear architectures and the structure-property relationships of polyelectrolye complex micelles (PCMs). In Chapter 2, we first focus on blocky polyelectrolyte architectures, specifically with the intention of creating double-diblock PCMs (D-PCMs) with unmatched charged block lengths for the first time. Using salt annealing, we were able to overcome barriers to D-PCM formation from blocky polyelectrolytes with charged block lengths up to 10x different. Using a combination of characterization techniques, we show that the cores grow via a unique interdependent mechanism where the block length of one diblock influences the ability of the other diblocks charged block to contribute to core size, aggregation number and density. This study provides a straightforward path to ordered PEC materials with unmatched charged block lengths and demonstrates the unique interdependent growth they undergo. For Chapter 3, we examined the role of lightly branched star polyelectrolytes in PECs. Charge density has been shown to directly influence the stability and mechanics of PECs and branched polyelectrolytes have higher charge density than linear counterparts. To understand if charge density could be modulated through lightly branched polymer architectures, we synthesize pairs of homologous polyelectrolytes to create model PEC systems of various architectures. We find that branched architectures influence the salt stability of PECs while leaving the mechanical properties and internal structure unchanged, suggesting that changing charge density via architecture alters PEC properties precisely, paving the way for more intentional PEC design. Chapter 4 focuses on the structure-property relationships of bottlebrush polyelectrolytes. We synthesize densely charged bottlebrush polyelectrolytes which form gel-like solids when complexes. To understand their gel-like rheological behavior, we delve into structural characterization using Cryo-TEM and SAXS. Together, they allow us to understand the structural development of bottlebrush PECs (BPECs) from the network level to the sidechain conformations as a function of salt. Our results in this chapter lay the groundwork for future studies into incorporating highly branched polyelectrolytes into PECs. In Chapter 5, we summarize our results and make the case for utilizing architecturally advanced polyelectrolytes to achieve otherwise unattainable structures in PEC materials. Combined, the results contained here broaden the PEC design space considerably, provide insight into molecular-level structure property relationships for PECs and pave the way for further study of advanced polyelectrolyte architectures within ordered PCMs and bulk PECs.