- Obsidian Arena is a web based game of gladiatorial combat. You manage a stable of five gladiators as you contend to be the champion. Earn gold to buy tactics and fighting styles from a selection 25 fighting styles and over 150 tactics. Train your warrior's skills and raise their attributes. Detailed blow by blow fight descriptions. Use strategy templates available to help beginners create their gladiator's strategies or create your strategy from scratch.