Real life disputes, negotiations and competitive situations involve multi-issue considerations in which the …nal outcome depends on the aggregated e¤ort over several dimensions. We consider two allocation systems, the I-system, in which each issue is disputed and award independently, and the A-system, in which all issues are aggregate in a single prize award. In the A-system, we propose a contest success function that aggregates the individuals' multi-issue e¤orts in a single outcome. Among other results, we found that the A-system tends to induce higher total e¤ort than the I-system.The model is also able to reproduce a large set of strategic behaviors. For instance, under decreasing returns to e¤ort, individuals maximize their payo¤s by distributing e¤ort over all issues, while under increasing returns to e¤ort, individuals focus on a single issue. Hybrid equilibria, in which one individual focus in a single issue while the other individual diversi…es e¤ort over all issues, may also emerge when individuals hold di¤erent returns to e¤ort. Strategic behavior is simultaneously in ‡uenced by the weight of each issue on the …nal outcome and by comparative advantages. Throughout the manuscript, we link our results with strategic behavior observed in electoral competition, i.e., "issue ownership", "issue divergence/convergence" and "common value issues". We expect that our …ndings will help researchers and practitioners to better understand the process of endogenous selection of issues in competitive contexts and to provide guidance in the implementation of the optimal allocation mechanism. JEL: C72, D72, D74, D81.