<function name="ShouldCollide" parent="GM" type="hook"> <ishook>yes</ishook> <description> Called to decide whether a pair of entities should collide with each other. This is only called if <page>Entity:SetCustomCollisionCheck</page> was used on one or both entities. Where applicable, consider using <page>constraint.NoCollide</page> or a [logic_collision_pair](https://developer.valvesoftware.com/wiki/Logic_collision_pair) entity instead - they are considerably easier to use and may be more appropriate in some situations. <warning>This hook **must** return the same value consistently for the same pair of entities. If an entity changed in such a way that its collision rules change, you **must** call <page>Entity:CollisionRulesChanged</page> on that entity immediately - **not in this hook.**</warning> ⤶ <note>To avoid causing all physics to break, try not to use inconsistent values when deciding collision results. One example of an inconsistent value is <page>Entity:Health</page>. Unless you call <page>Entity:CollisionRulesChanged</page> immediately after that value changing, all physics will break.</note>⤶ <bug issue="642">This hook can cause all physics to break under certain conditions.</bug> </description> <realm>Shared</realm> <predicted>Yes</predicted> <args> <arg name="ent1" type="Entity">The first entity in the collision poll.</arg> <arg name="ent2" type="Entity">The second entity in the collision poll.</arg> </args> <rets> <ret name="" type="boolean">Whether the entities should collide.</ret> </rets> </function> <example> <code> hook.Add( "ShouldCollide", "CustomCollisions", function( ent1, ent2 ) -- If players are about to collide with each other, then they won't collide. if ( ent1:IsPlayer() and ent2:IsPlayer() ) then return false end end ) </code> </example>