Aka, collision, because real physics: why bother? Quake was good enough. Hence, lots of links talking about BSPs.

λ = really good
ϕ = video

General

• Geometric Primitives - Game Math | Covers bounding boxes, AABB etc.
• Bounding Volumes | In-depth series on collision, includes implementation code
• "Physics Tutorials" | See the sidebar
• Game Physics Cookbook - Gabor Szauer | Includes tons of code
• Frustum Culling | Discusses bounding volumes as well
• Geometric Tests - Game Math
• Physics Tutorial 4: Collision Detection
• Physics Raycasting.pdf
• Reddit comment describing Collision λ
• Dynamic Bounding Volume Hierarchies
• Collision Detection & Intersection Tests
• Spatial Partition
• 3dcollisions
• Physically Based Modeling - David Baraff
• Capsule Collision Detection
• Improved Collision detection and Response - Kasper Fauerby

Octotrees

• Introduction to Octrees
• Octotree algorithm visualisation & explanation ϕ
• Octotree collision discussion
• Project implementing Octotrees for "simple 3d physics"
• Game Engine discussing Octotrees
• OpenGL Tutorial - 25 - Octree Part 1 (Introduction/Creation) ϕ
• OpenGL Tutorial - 29 - Octree Part 4 ϕ
• Octrees - 3D Collisions in GameMaker ϕ
• Octree-based Collision Detection in iMSTK
• Collision Detection by Octree ϕ

Chen Huang

• Collision System Part 1: Collision Detection and Response Against Static Mesh
• Collision System Part 2: Sparse Hash-Based Grid Partitioning, Multithreading, and Future
• Engine Work: Collision Debug System
• Engine Work: GJK-based Collision Detection & Response
• Engine Work: Collision Wrap-up

Ingemar Ragnemalm

• Beachball Physics - Ingemar Ragnemalm
• Polygons feel no pain Volume 1 - Ingemar Ragnemalm
• Polgyons feel no pain Volume 2 - Ingemar Ragnemalm

Scene Graph

• Scene Graph - LearnOpenGL λ
• WTF is a Scene Graph? - Jamie Kuppens
• Scene Graph - WebGL

BSP

• Broad-Phase Collision Detection Using Semi-Adjusting BSP-trees
• Self-Customized BSP Trees for Collision Detection
• BSP Collision Detection As Used In MDK2 and NeverWinter Nights
• Binary Space Partitioning Tree Tutorial
• When to use Binary Space Partitioning, Quadtree, Octree?
• Quake Map Format
• From BSP To ESP – How S3ctor Abused Quake Editors to Redefine the Morrowind Modding Experience
• Collisions with BSP geometry - Stack Overflow
• BSP Tree - BeyondUnreal
• Binary Space Partioning Trees and Polygon Removal in Real Time 3D Rendering - Samuel Ranta-Eskola λ
• Binary Space Partitioning - Valve λ
• A simplified yet complete explanation of BSP trees and their uses λ
• Quake 2 BSP File Format - flipcode λ
• BSP Trees: The Magic Behind Collision Detection in Quake - Matt's Ramblings ϕ
• Scene Management Using BSP Trees - Ubbo Visser λ