A joint connection that accommodates relative lateral and vertical movement between connected walls during seismic activity, the joint connection comprising: a first plate assembly having (a) two or more parallel first connection plates (18a, 18b) each including a first diagonal slot formed therethrough that extends along a first diagonal direction and (b) a first securable plate to which the first connection plates are immovably fixed, the first diagonal slots being aligned with each other, the first securable plate being secured to a first support member (12a or 14a) that is a part of or connected to a first wall, the two or more first connection plates extending along a lateral direction from the first securable plate and in parallel first planes, the first diagonal slot being diagonal relative to a vertical direction which is orthogonal to the lateral direction; a second plate assembly having (a) at least one second connection plate (16a or 16b) the at least one second connection plate being positioned between two of the first connection plates and including a second diagonal slot formed therethrough that extends along a second diagonal direction, and (b) a second securable plate to which the at least one second connection plate is immovably secured, the second securable plate being secured to a second support member (12b or 14b) that is a part of or connected to a second wall, each second connection plate (16a, 16b) extending along the lateral direction in a respective second plane that is parallel to the first planes, the second diagonal slot being diagonally opposite to the first diagonal slot relative to the vertical direction such that the first diagonal direction and the second diagonal direction cross each other, each second connection plate being positioned such that at least a portion of its second diagonal slot aligns with each other second diagonal slot and overlaps a portion of each first diagonal slot; and a pin assembly clamping together the first plate assembly and the second plate assembly with a clamping force and including a pin extending through each first diagonal slot and each second diagonal slot, the joint connection permitting lateral slippage along the lateral direction, vertical slippage along the vertical direction, or both, of the first plate assembly and the second plate assembly relative to each other when the joint connection is subject to a seismic load but without significant loss of the clamping force. a first plate assembly having (a) two or more parallel first connection plates (18a, 18b) each including a first diagonal slot formed therethrough that extends along a first diagonal direction and (b) a first securable plate to which the first connection plates are immovably fixed, the first diagonal slots being aligned with each other, the first securable plate being secured to a first support member (12a or 14a) that is a part of or connected to a first wall, the two or more first connection plates extending along a lateral direction from the first securable plate and in parallel first planes, the first diagonal slot being diagonal relative to a vertical direction which is orthogonal to the lateral direction; a second plate assembly having (a) at least one second connection plate (16a or 16b) the at least one second connection plate being positioned between two of the first connection plates and including a second diagonal slot formed therethrough that extends along a second diagonal direction, and (b) a second securable plate to which the at least one second connection plate is immovably secured, the second securable plate being secured to a second support member (12b or 14b) that is a part of or connected to a second wall, each second connection plate (16a, 16b) extending along the lateral direction in a respective second plane that is parallel to the first planes, the second diagonal slot being diagonally opposite to the first diagonal slot relative to the vertical direction such that the first diagonal direction and the second diagonal direction cross each other, each second connection plate being positioned such that at least a portion of its second diagonal slot aligns with each other second diagonal slot and overlaps a portion of each first diagonal slot; and a pin assembly clamping together the first plate assembly and the second plate assembly with a clamping force and including a pin extending through each first diagonal slot and each second diagonal slot, the joint connection permitting lateral slippage along the lateral direction, vertical slippage along the vertical direction, or both, of the first plate assembly and the second plate assembly relative to each other when the joint connection is subject to a seismic load but without significant loss of the clamping force.