Every five player levels is grouped into a Tier. At present there are ten tiers, representing a possible 50 levels.
Enumeration
| Levels | Tier |
|---|---|
| 1-5 | 1 |
| 6-10 | 2 |
| 11-15 | 3 |
| 16-20 | 4 |
| 21-25 | 5 |
| 26-30 | 6 |
| 31-35 | 7 |
| 36-40 | 8 |
| 41-45 | 9 |
| 46-50 | 10 |
Mathematical formula1
Tier = CEILING( Level / 5 )
Explanation
The effectiveness of rations depends on your current tier. Rations of a tier equal to yours will have full effect; lower-tier rations will regenerate only a portion of your stats, and will grant the "Well Fed" buff for a shorter time. The effectiveness of medical stims similarly decreases, and toxicity increases, when you are a higher tier.
Weapons and armor are similarly grouped into Tiers. The worst equipment from any tier will generally be better than the best equipment from a lower tier. This includes even Epic equipment, which is generally the best for its tier but still inferior to higher-tier equipment.