Board Thread:Questions and Answers/@comment-38146049-20190805232851/@comment-39394247-20190818070346

Shield: RBE that can be blocked = 25 * round^2 (e.g. round 20: 10000 RBE, which is actually useful)

Road spikes: 5 * round^2 each, 5.5 and then 6 for the higher tiers.

You gain +2 * round^2 lives at the end of every round.