Conflict. Combat. Contention. It's seen humans at their worst, and inspired some of the most sublime human artistic creations. Well, you don't have to go that far this. A cool t-shirt design is enough. Think more like Bugs Bunny saying "of course you realize, this means war" rather than Full Metal Jacket. It can be funny, historical, cute, heartfelt, serious, whatever... BUT know that we won't hesitate to reject anything we find insensitive or in poor taste.
No text-only designs.
No cats, Star Wars, Doctor Who, or Mario.
No cranberry tees.