PROMOTION TREES
Units advancing through branching upgrade paths — the recruit who becomes rifleman or medic, class promotions at level thresholds, veteran units choosing specializations.
- SOLO-DEV COST MEDIUM
- TIMING TURN-BASED
- COMMON IN TACTICS · STRATEGY · RPG · ROGUELIKE
Fire Emblem's class promotions are the genre backbone (the village myrmidon becoming a swordmaster is the series' power fantasy), XCOM's rank-up ability choices fork every soldier into a build, Advance Wars-likes and autochess games promote units by merging or veterancy, and Darkest Dungeon-likes tier heroes through resolve levels. Designers use promotion trees because they convert generic units into invested characters: each branch point is a small authorship act (my sniper, whom I built for squadsight), and the accumulated choices make veteran units genuinely irreplaceable — which is exactly what gives permadeath its teeth and roster management its drama. Trees also pace complexity (new abilities arrive one choice at a time rather than as a wall) and multiply roster variety from a small unit set, since two max-rank soldiers of the same class can play entirely differently. The fork structure matters: exclusive branches create identity and replay value precisely because you can't have both. Key decisions: branch exclusivity and respec policy (locked choices make weight; free respecs make experimentation — pick per genre stakes), how early the first fork arrives (immediate forks overwhelm; late forks waste the mechanic), and telegraphing — players need to see what the branches become before choosing, or the choice is a coin flip wearing a menu. Pitfall: false branches — when one path is strictly better or the community solves the tree into a single build order, the fork is a quiz with a correct answer, taxing newcomers while veterans click through; branches survive only while both sides answer different real problems the campaign actually poses.