Sorry for pasting instead of an attachement. The specs for glDrawRangeElementsBaseVertex [1] say this case (array out of bounds) should be handled like this: "Index values lying outside the range [start, end] are treated in the same way as glDrawElementsBaseVertex. " The specs for glDrawElementsBaseVertex [2] don't say anything about this case (obviously since this function doesn't imply any size constrains for the array). So it seems like it is indeed a Bug in the game to try to address this index element but also the operation should not crash and its unspecified behaviour. Perhaps radeonsi should handle it the same as other mesa drivers to for the sake of cosistency. [1] https://www.opengl.org/sdk/docs/man/html/glDrawRangeElementsBaseVertex.xhtml [2] https://www.opengl.org/sdk/docs/man/html/glDrawElementsBaseVertex.xhtml