Tilt

Tilt is a gold skull featured in Halo 3, Halo 3: ODST, Halo: Reach, Halo 4 and Halo 5: Guardians. It serves to magnify the effect of impacts on movable objects, when activated.

Halo 3, Halo 3: ODST, Halo: Reach, Halo 4 and Halo 5: Guardians
The skull in its appearances in first-person shooter Halo installments causes the weaknesses and resistances to be both boosted. So using the correct weapon types for each enemy is a lot more important.